LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 

Class 


Columbia  SUmbnsttu  Hectares 


POWER 

THE    HEWITT   LECTURES 
1909-1910 


COLUMBIA 

UNIVERSITY  PRESS 

SALES  AGENTS 

NEW  YORK: 

LEMCKE  &  BUECHNER 
80-32  WEST  27ra  STREET 

LONDON : 

HENRY  FROWDE 
AMEN  CORNER,  E.G. 


COLUMBIA    UNIVERSITY  LECTURES 


POWER 


BY 


CHARLES   E.    LUCRE,   PH.D. 

PROFESSOR    OF    MECHANICAL    ENGINEERING 
COLUMBIA    UNIVERSITY 


gork 
THE    COLUMBIA   UNIVERSITY   PRESS 

1911 

All  rights  reserved 


COPYRIGHT,  1911, 
BY   THE   COLUMBIA   UNIVERSITY   PKESS. 


Set  up  and  electrotyped.     Published  April,  1911. 


Nortoooti 

J.  8.  Gushing  Co.  —  Berwick  &  Smith  Co. 
Norwood,  Mass.,  U.S.A. 


PREFACE 

IT  is  the  object  of  the  series  of  lectures  included  in  this 
volume  to  point  out  the  enormous  effect  that  the  substi- 
tution of  mechanical  power  for  hand  and  animal  labor 
has  had  on  the  organization  of  society  and  the  conditions 
of  living,  and  by  presenting  the  development  of  power 
machinery  to  show  what  sort  of  ideas  have  produced  this 
result.  The  effect  of  power  machinery  is  soon  told  and 
readily  understood ;  but  it  is  not  so  easy,  though  far  more 
important,  to  show  how  the  men  who  are  responsible  for 
what  lias  been  done  have  thought  and  worked,  and  with 
what  kind  of  things  and  with  what  reasoning  those  men 
must  deal  who  are  to  take  up  the  responsibility  for  future 
progress.  The  bulk  of  the  subject-matter,  accordingly, 
is  concerned  with  the  apparatus  and  machinery  for  the 
converting  of  natural  energy  in  any  of  its  available  forms 
into  useful  Avork,  together  with  the  physical  processes  for 
the  execution  of  which  that  apparatus  was  devised. 

C.  E.  L. 


v 

ooonnr; 
**  ^  U  i>  (J  3 


CONTENTS 

SECTION  PAGE 

I.     THE    RELATION    OF    MECHANICAL    POWER    AND    MA- 
CHINERY TO  SOCIAL  CONDITIONS         .         .         .         .11 
II.     MEANS  EMPLOYED  FOR  THE  SUBSTITUTION  OF  POWER 

FOR  THE  LABOR  OF  MEN 29 

III.  ESSP;NTIAL  ELEMENTS  OF  STEAM-POWER  SYSTEMS        .       66 

IV.  PRINCIPLES  OF  EFFICIENCY  IN  STEAM-POWER  SYSTEMS     101 
V.     PROCESSES  AND  MECHANISM  OF  THE  GAS-POWER  SYS- 
TEM          142 

VI.     ADAPTATION  OF    FUELS  FOR  THE   USE   OF   INTERNAL 

COMBUSTION  ENGINES 177 

VII.     WATER-POWER  SYSTEMS  AND  BASAL  HYDRAULIC  PRO- 
CESSES   ..........     211 

VIII.     SOCIAL   AND    ECONOMIC  CONSEQUENCES   OF  THE   SUB- 
STITUTION OF  POWER  FOR  HAND  LABOR  .         .         .     266 

INDEX  305 


vii 


POWER 


THE  RELATION   OF  MECHANICAL   POWER  AND  MACHINERY 
TO  SOCIAL   CONDITIONS 

RECORDED  or  unrecorded  history,  the  story  of  things 
that  have  happened,  with  explanations  of  the  probable 
reason,  may  be  regarded  as  a  most  useful,  if  not  a  nec- 
essary, guide  to  the  conduct  of  present-day  affairs; 
whether  it  be  concerned  with  wars  and  governments 
or  the  customs  and  mode  of  living  of  the  people ; 
whether  written  in  books  carrying  the  title  of  history 
or  told  by  the  old  to  the  young,  treating  of  ancient 
times  or  the  events  of  yesterday.  For  a  long  time 
writers  of  history  were  content  with  records  of  armies 
and  battles,  and  their  relation  to  the  fall  of  one  empire 
and  the  rise  of  another.  Little,  if  any,  attention  was 
given  to  such  ordinary  questions  as  the  sort  of  food 
the  people  ate,  the  kind  of  clothes  they  wore,  of  what 
sicknesses  they  died,  at  what  occupation  they  labored, 
and  with  what  tools  to  assist  them,  what  compensation 
they  received,  and  how  the  product  of  their  labor  was 
obtained  by  the  non-producer,  —  all  of  these  questions 
of  far  more  vital  importance  to  the  welfare  of  the 
average  individual  than  the  quarrels  of  nations.  While 
some  little  information  of  -thi^  class  may  bp»  found  in 
B  i ,; 


2  POWER 

general  literature,  not  ordinarily  classed  as  history, 
the  topics  there  discussed  seldom  refer  to  the  daily 
work  of  the  mass  of  the  people,  by  means  of  which  the 
whole  population  was  fed,  clothed,  and  housed,  or  the 
relation  of  these  questions  now  generally  classified  as 
industrial  to  the  social  or  governmental  organizations, 
the  welfare  of  the  individual,  or  changes  of  state. 
Modern  historians,  however,  are  waking  up  to  the  fact 
that  present  conditions  have  been  brought  about  not 
so  much  by  the  victories  of  war  as  by  the  practice  of 
every-day  acts  of  peace,  and  that  a  diagram  of  a  loom 
for  weaving  cloth  may  really  be  a  more  valuable  thing 
to  study  than  a  map  of  the  battle  of  Waterloo. 

There  seems  to  be  little  doubt  now  that  industrial 
conditions  are  of  primary  importance  in  shaping  the 
various  conditions  of  human  affairs,  and  are  funda- 
mental to  the  mere  existence  of  government,  but  this 
did  not  appear  so  clearly  in  early  times.  In  the  days 
when  the  great  body  of  the  people  were  farmers,  when 
little  mining  was  practised  and  practically  no  manu- 
facturing, about  the  only  unusual  or  extraordinary 
happenings  were  the  wars,  so  it  is  not  surprising  that 
a  history  of  the  period  should  be  a  record  of  these  con- 
flicts. Later  on,  however,  things  changed,  industrial 
affairs  assuming  more  importance  as  factories  were 
built,  drawing  men  from  farms  and  concentrating 
them  in  factory  towns,  and  stimulating  the  develop- 
ment of  steamships  and  railroads  to  bring  raw  materials 
to  the  factories  and  to  distribute  their  products,  giving 
more  and  varied  employment  to  others,  and  supplying 
all  with  new  forms  of  the  necessaries  and  luxuries  of 
life,  and  ccjrn^letely  changing  the  whole  social  organism. 


POWER  AND   MACHINERY  3 

The  great  change  in  conditions,  which  made  those 
things  which  formerly  seemed  all-important  assume 
minor  significance,  and  accented  the  truly  greater 
importance  of  industrial  affairs,  began  a  little  over 
a  century  and  a  half  ago,  with  the  invention  of  spinning 
and  weaving  machinery  and  the  steam-engine  to  drive 
it.  Tracing  from  that  time  the  progress  of  the  sub- 
stitution of  mechanical  power  and  machinery  for  hand 
labor,  by  which  those  things  that  people  want  can  be 
produced  better  and  cheaper  than  ever  before,  as  well 
as  new  things  previously  not  thought  of,  but  which 
are  wanted  as  soon  as  seen,  will  serve  to  explain  modern 
conditions  as  no  other  study  can.  Instructive  as  such 
a  review  of  industrial  history  may  be,  it  is  as  nothing 
compared  to  the  value  of  an  understanding  of  the  in- 
dustrial conditions  of  the  present  time.  It  is  far  better 
to  know  how  a  hat  is  made,  a  trolley  car  works,  or  the 
fruit  of  California  can  be  sold  cheaply  in  New  York, 
three  thousand  miles  away,  than  any  of  the  facts  of 
history,  though  the  latter  may  precede  and  make  easier 
the  comprehension  of  the  more  complex  present.  Re- 
ferring to  the  importance  of  these  industrial  changes, 
which  is  slowly  but  surely  becoming  accepted  as  it 
should  be,  is  a  well-worded  statement  in  Robinson  and 
Beard's  " Modern  Europe." 

"The  story  of  mechanical  invention  is  in  no  way 
inferior  in  fascination  and  importance  to  the  more 
familiar  history  of  kings,  parliaments,  wars,  and  con- 
stitutions. The  chief  factors  in  it  never  stirred  an 
assembly  by  their  fiery  denunciation  of  abuses,  or  led 
an  army  to  victory,  or  conducted  a  clever  diplomatic 


4  POWER 

negotiation.  On  the  contrary,  their  attention  was 
concentrated  upon  the  homely  operations  of  every-day 
life;  the  housewife  drawing  out  her  thread  with  dis- 
taff or  spinning-wheel,  the  slow  work  of  the  weaver 
at  his  primitive  loom,  the  miner  struggling  against 
the  water  which  threatened  to  flood  his  mine.  They 
busied  themselves  perseveringly  with  wheels,  cylinders, 
bands,  and  rollers,  patiently  combining  and  recombining 
them  until,  after  many  discouragements,  they  made 
discoveries  destined  to  alter  the  habits,  ideas,  and 
prospects  of  the  mass  of  the  people  far  more  profoundly 
than  all  the  edicts  of  the  National  Assembly,  or  all  the 
conquests  of  Napoleon  taken  together. " 

The  often-heard  characterization  of  our  times  as 
the  " industrial  age"  and  of  our  most  influential  citi- 
zens as  " captains  of  industry"  are  indications  of 
growing  respect  for  the  manufacturing  and  transpor- 
tation industries  not  merely  as  occupations  or  means 
of  employment,  but  as  world-shaping  forces  stronger 
than  armies  and  navies,  and  marks  of  appreciation  of 
the  fact  that  the  training  of  engineers  is  more  important 
than  that  of  generals.  It  is  not  so  generally  realized, 
however,  that  all  this  would  be  quite  impossible  without 
power-generating  machinery,  which,  receiving  the  water 
of  the  river  or  the  heat  of  fuel  as  sources  of  energy, 
changes  them  under  man's  control,  and  finally  turns 
the  wheels  of  industry.  It  is  difficult  to  believe  that 
any  one  with  ordinary  natural  curiosity,  after  having 
his  attention  drawn  to  these  facts,  and  knowing  that 
practically  every  article  that  he  uses,  especially  in  cities, 
is  power  produced,  at  least  in  part,  can  fail  to  inquire 


POWER  AND   MACHINERY  5 

how  it  was  brought  about ;  in  just  what  way  man  has 
succeeded  in  harnessing  nature  to  do  his  will ;  for  the 
employment  of  power-generating  machinery  is  a  demon- 
stration of  his  control  over  those  forces  of  nature  that 
once  struck  fear  into  the  hearts  of  men  by  lightning, 
fire,  and  flood. 

When,  in  addition,  it  may  be  promised  that  an  exam- 
ination of  the  power-generating  processes  and  machin- 
ery, on  which  so  much  of  general  interest  and  personal 
welfare  depend,  will  also  reveal  the  working  of  broad, 
philosophic  law  applicable  to  all  human  affairs  with 
profit,  the  systematic  location  and  reduction  of  waste 
in  all  things,  then  mere  curious  questioning  may  well 
be  expected  to  yield  to  enthusiastic  study. 

We  are  every  moment  surrounded  by  manufactures 
and  results  of  mechanical  power  and  driven  machinery 
in  almost  infinite  variety.  Not  only  are  the  clothes, 
hats,  and  shoes  we  wear  produced  by  power-driven 
machinery,  at  least  in  part,  but  so  also  are  all  the  fabrics 
of  the  household,  —  linens,  carpets,  and  hangings,  the 
furniture,  glass,  chinaware,  and  metal  house  furnish- 
ings, and  practically  all  that  enters  into  the  making  of 
the  house  itself,  —  cement,  brick,  pipe,  nails,  furnaces, 
radiators,  and  lamps. 

In  addition,  we  use  power-generated  electric  light 
and  bathe  in  power-pumped  water,  ride  in  powered 
cars  and  boats,  make  war  with  power-made  guns  and 
ships  consisting  of  several  million  dollars'  worth  of 
machinery  each.  The  very  food  on  our  tables  is  drawn 
from  the  waters,  forests,  and  farms  of  the  earth  by 
highly  developed  systems  of  transportation,  preserved 
by  machine  processes  or  stored  between  production 


6  POWER 

and  need  in  power-cooled  refrigerators,   and  we  cool 
our  beverages  by  manufactured  pure  ice. 

In  order  that  we  may  just  exist,  we  require  a  supply 
of  food  and  clothing,  while  comfortable  living  adds 
the  necessity  of  housing  with  heat,  light,  and  water, 
finer  clothing  and  more  choice  food.  To  supply  the 
necessities,  comforts,  and  luxuries  of  present-day  life 
requires  a  most  complex  series  of  operations  by  men 
with  knowledge  of  nature's  stores,  and  of  the  means 
by  which  they  can  be  brought  from  the  hidden  places 
at  the  extremes  of  distance,  and  changed  when  neces- 
sary to  that  form  which  may  be  desired.  Seldom  are 
nature's  stores  of  substances  found  in  suitable  form 
for  use;  but  man  early  learned  to  change  their  form 
by  hand,  and  devised  tools  to  assist  in  the  cutting  of 
stones,  the  weaving  of  grasses  and  fibrous  wool  of  ani- 
mals into  cloth;  and  later  to  use  natural  energy  to 
assist,  by  baking  clay  to  form  bricks  and  pots,  and  by 
heating  certain  rocks  to  get  copper  and  iron,  though 
for  a  long  time  there  was  no  realization  of  the  fact  that 
the  use  of  fire  to  assist  change  of  form  was  a  demon- 
stration that  heat  was  one  kind  of  natural  energy,  or 
that  it  could  be  made  to  do  common  work  of  lifting, 
pushing,  and  pulling. 

A  still  earlier  though  similarly  unconscious  use  of 
heat  energy  was  made  when  man  planted  seeds  in  the 
earth  to  obtain  a  supply  of  food.  These  seeds  grew, 
and  in  the  growing  the  substances  of  the  earth  in  which 
the  seed  was  placed,  together  with  the  air  and  water 
which  surrounded  it,  were  transformed  into  the  potato 
and  the  tree  by  the  chemical  and  molecular  forces 
derived  from  the  energy  of  the  sunshine,  binding  up 


POWER  AND  MACHINERY  7 

the  sun's  energy  in  the  new  plant  form  taken  by  the 
primary  inanimate  substances.  This  change  of  sub- 
stance form,  through  the  assistance  of  natural  energy, 
by  which  the  useless  may  be  made  useful,  and  of  which 
life  itself  is  the  best  example,  taught  a  lesson  unlearned 
through  countless  ages,  during  which  but  little  progress 
toward  what  we  are  pleased  to  term  "  civilization  "  was 
made.  No  one  dreamed  that  energy  was  being  used, 
or  even  that  there  was  such  a  thing,  in  those  days,  and 
it  is  not  too  much  to  say  that  the  conception  of  energy 
which  recognizes  heat,  work,  electricity,  magnetism, 
sound,  and  light  as  interchangeable  energy  manifesta- 
tions was  one  of  the  most  significant  in  point  of  results 
that  the  world  has  ever  seen. 

The  discovery  that  energy  was  available  in  nature 
for  the  doing  of  man's  work  is  sometimes  traced  to  his 
natural  indolence  when  he  placed  sails  on  boats,  and 
paddle-wheels  under  waterfalls  to  lift  weights,  even 
though  no  idea  existed  that  the  capacity  of  the  moving 
water  and  moving  air  to  do  these  things  was  proof  of 
the  existence  of  energy  in  nature,  and  exactly  similar 
to  the  capacity  of  fire  to  melt  things  or  extract  metals 
from  ores. 

From  the  practice  of  these  simple  processes  of  form 
changing,  such  as  weaving  and  the  application  of  wind 
and  water  energy  to  the  service  of  men,  there  is  a  long 
period  during  which  no  real  progress  worth  mentioning 
was  made,  and  which  came  to  an  end  only  with  the 
general  realization,  first,  of  the  possibility  of  devising 
combinations  of  sticks  and  metal  parts  to  reproduce 
the  movements  of  hands  and  fingers  and  eliminate 
the  guidance  of  the  eye ;  in  short,  to  make  things  wanted 


8  POWER 

from  other  things  available;  and  secondly,  that  the 
heat  of  burning  fuel,  if  properly  applied  to  other  sub- 
stances and  metal  parts,  was  capable  of  doing  the  same 
sort  of  work  as  the  waterfall  and  the  wind. 

The  general  process  of  changing  useless  materials 
into  useful  and  serviceable  things  is  termed  to-day 
"manufacturing,"  when  carried  out  systematically 
and  repeatedly  in  the  same  way,  while  the  processes 
by  which  natural  energy  of  whatever  form  can  be  made 
to  do  man's  work  are  called  rather  incorrectly  "  power 
generation . ' '  Together  these  processes  of  manufacturing 
and  the  generation  of  power,  carried  out  in  the  machin- 
ery of  manufactures,  perform  the  function  of  changing 
natural  things  into  other  things  that  people  want; 
so  man  has  learned  in  part  nature's  own  lesson  of 
organic  life  and  applied  it  to  his  needs  and  pleasures. 

Culture  and  the  full  enjoyment  of  life  are  possible 
only  when  the  demands  for  the  necessities  have  been 
satisfied;  or,  speaking  more  broadly,  national  pros- 
perity is  a  necessary  prerequisite  to  civilization,  and 
that  nation  is  most  permanently  prosperous  in  which 
production  of  wealth  is  the  more  universal  occupation  ; 
wealth  derived  primarily  from  the  farm,  the  sea,  the 
mine,  and  the  forest,  the  raw  materials  of  which  are 
augmented  in  value  by  manufacture,  giving  rise  to 
transportation  and  commerce.  In  all  of  these  indus- 
tries, basal  to  national  security  and  happy  living, 
mechanical  power  plays  a  part,  more  important  in 
some  than  in  others,  but  an  important  part  in  all. 
Practically  all  our  fish  products  are  gathered  in  power 
boats  to-day ;  mines  that  can  raise  the  ore  to  the  sur- 
face without  power  are  rare,  and  still  more  rare  are  the 


POWER  AND   MACHINERY  9 

ores  that  can  be  reduced  to  metal  without  it ;  the 
farmer  is  resorting  more  and  more  to  power,  one  manu- 
facturer alone  last  year  having  sold  30,000  gasolene 
engines  for  farm  use.  It  is,  however,  the  other  two 
industries  that  are  most  dependent  on  power ;  manu- 
facturing owes  its  very  existence  to  our  ability  to  gen- 
erate, apply,  and  control  power  economically,  while 
power  is  the  prime  element  in  transportation  over  land 
and  water.  These  two  great  businesses  of  making 
things  and  moving  them,  now  classified  as  the  indus- 
tries of  manufacturing  and  transportation,  underlying 
practically  all  of  commerce,  owe  their  present  state  to 
power,  and  their  future  is  largely  a  power  problem. 

Clearly  as  does  a  review  of  these  things  indicate  our 
dependence  on  the  use  of  power  applied  in  the  indus- 
tries, it  will  be  helpful  in  reaching  a  measure  of  the 
magnitude  of  the  interests  involved  to  examine  some 
statistics  drawn  from  the  last  United  States  Census 
Reports  for  the  year  1905.  From  these  reports  it 
appears  that  the  manufacturing  and  steam-railroad 
industries  alone  represent  a  capital  valuation  of  nearly 
twenty-four  billion  dollars,  about  equally  divided. 
The  railroads  of  the  country  alone  represent  a  mileage 
of  213,932  miles,  or  enough  to  go  eight  and  a  half  times 
around  the  earth,  while  the  manufacturing  industries 
reported  over  two  hundred  thousand  establishments. 
These  together  gave  employment  to  nearly  eight 
million  people,  about  six  million  in  manufacturing 
and  over  one  and  a  half  million  on  the  railroads,  paying 
them  on  the  average  $640  each  on  the  railroads,  and 
$550  in  the  manufacturing  classes,  the  manufacturers' 
pay-rolls  aggregating  over  three  billion  dollars  ($3,186,- 


10  POWER 

301,763)  yearly.  Raw  materials  from  mine,  farm, 
forest,  and  sea  used  by  the  manufacturers  cost  them 
over  eight  and  a  half  billion  dollars  ($8,503,949,756), 
and  the  processes  through  which  they  were  transformed 
increased  their  value  about  70  per  cent,  adding  to  the 
wealth  of  the  country  over  six  billion  dollars,  the  manu- 
factured goods  becoming  worth  nearly  fifteen  billion 
dollars  ($14,802,147,087).  These  industries  now  em- 
ploy power  to  an  extent  approaching  50,000,000  h.  p., 
and  the  whole  is  not  reported,  but  for  each  horse-power 
that  is  reported  the  products  were  worth  $1152,  and 
$248  in  wages  were  paid  in  the  manufacturing  industry. 
The  present  total  is  estimated  from  the  following 
figures,  Table  I,  which  do  not  include  automobiles, 
hoisting,  pumping,  and  compressing  engines,  and  in- 
dependent engines  used  in  buildings  not  engaged  in 
manufacturing,  such  as  hotels,  which  should  be  added, 
and  which  would  considerably  increase  the  reported 
total,  while  the  total  to-day  must  be  much  increased 
over  the  census  year  of  1905,  as  the  rate  at  which  the 
use  of  power  has  been  increasing  has  been  itself  on  the 
increase  since  the  Civil  War. 


POWER  AND   MACHINERY  11 


TABLE   I 

POWER  IN  USE  BY  LAST  CENSUS.    CORRECTED  BY  H.  ST.  CLARE 

PUTNAM 

Manufactures  (1905) 12,765,594 

Mines  and  quarries  (1902) 2,753,555 

Street  railways  (1902) 1,359,289 

Electric  light  and  power  stations  (1902) 1,845,048 

Telephone,  telegraph,  and  fire  alarm 3,148 

Custom  flour,   grist,   and  sawmills,   and  industries 

omitted  from  Census 883,685 

Naval  vessels  (1905) 777,598 

Licensed  merchant  vessels  (1905) 2,608,270 

Locomotives  (1904)  equivalent 3,750,000 


Total  horse-power  accounted  for 26,746,187 

In  reporting  the  manufacturing  industries,  many 
establishments  were  omitted  in  accordance  with  the 
Bureau's  definition  of  a  factory  as  uan  establishment 
in  which  there  is  an  association  of  separate  occupations 
to  facilitate  the  combination  of  the  processes  into  which 
the  manufacture  is  divided,  and  producing  goods  for 
the  general  market  stock  rather  than  on  the  order  of 
an  individual."  This  definit'on  excludes  the  small 
shoemaker,  milliner,  all  the  building  trades,  and  sim- 
ilar kinds  of  business. 

The  greatest  manufacturing  industries  may  be  judged 
by  either  the  number  of  wage-earners  or  the  value  of 
products,  and  on  this  basis  the  following  two  tables 
are  offered,  from  which  it  appears  that  each  of  five 
groups  of  industries  employed  over  two  hundred  thou- 
sand wage-earners,  and  each  of  six  industries  produced 
goods  valued  at  half  a  billion  dollars  or  more. 


12 


POWER 


TABLE  II 

GREAT  INDUSTRIES  BY  WAGE-EARNERS 
INDUSTRIES  EMPLOYING  OVER  200,000  WAGE-EARNERS 


INDUSTRY 

NUMBER  OF 
WAGE-EARNERS 

Lumber  and  timber  products 

404  626 

Foundry  and  machine  shops 

402  919 

Cotton  goods 

315  874 

Steam  railroad  shops       

236,900 

Iron  and  steel  works  and  rolling-mills   .... 

207;562 

TABLE   III 

GREAT  INDUSTRIES  BY  VALUE  OF  PRODUCT 
INDUSTRIES  WITH  PRODUCTS  WORTH  A  HALF  BILLION  DOLLARS  YEARLY 


INDUSTRY 


VALUE  OF 
PRODUCTS  YEARLY 


Slaughtering  and  meat  packing  . 
Foundry  and  machine  shops  .  . 
Flour  and  grist  mill  products 
Iron  and  steel  works,  rolling-mills 
Lumber  and  timber  products  .  . 
Cotton  goods 


$801,757,137 
799,862,588 
713,033,395 
673,965,026 
580,022,690 
450,467,704 


To  supply  the  manufacturing  industries  with  raw 
materials  there  are  supported  the  other  industries  of 
lumbering,  mining,  farming,  and  fishing,  each  of  which 
contributed,  as  shown  in  Table  IV;  over  94  per  cent 
coming  from  farms  and  mines. 


POWER  AND   MACHINERY 


13 


TABLE   IV 
SOURCE  OF  RAW  MATERIALS  AND  THEIR  DISTRIBUTION 


SOURCE 

YEARLY  VALUE 

PER  CENT 

Farm   
Forest 

$2,492,836,646 
163  464  677 

81.2 

50 

Mine 

471  118  181 

13  4 

Sea  

13.715,086 

.4 

$3,141,134,590 

100.0 

FARM  PRODUCTS 

PER 

CENT 

SEA  PRODUCTS 

PER 

CENT 

Food  products  industry 

63.6 

Food  products     .     .     . 

83.1 

Textile  industry      .     . 

18.6 

Chemicals        .... 

1.9 

Leather  goods  industry 

6.4 

Miscellaneous       .     .     . 

15.0 

Liquors  and  beverages 

2.4 

Chemicals      .... 

3.9 

Tobacco    

4.0 

Miscellaneous     .     .     . 

1.1 

MINE  PRODUCTS 

PER 

CENT 

FOREST  PRODUCTS 

PER 
CENT 

Iron  and  steel  goods  . 

23.9 

Lumber  products      .     . 

53.8 

Chemicals    

33.9 

Paper  and  printing  .     . 

15.6 

Clay,  glass,  and  stoneware 

5.3 

Chemicals    

5.6 

Other  metal  products 

29.8 

Vehicles      

1.6 

Miscellaneous  .... 

7.1 

Miscellaneous       .     .     . 

23.4 

Not  only  does  the  manufacturing  process  add  to  the 
wealth  of  the  country  by  increasing  the  value  of  the 
materials  used  nearly  80  per  cent,  but  it  also  gives  a 


14  POWER 

value  to  the  raw  materials  which  they  did  not  previously 
possess  in  their  original  state.  There  would  be  little 
demand  for  iron  ore  without  the  means  of  extracting 
the  iron  and  making  from  it  things  that  people  want ; 
fruit,  vegetables,  and  fish  are  produced  at  definite 
seasons  and  are  worth  more  since  means  of  preserva- 
tion and  cold  storage  were  developed  than  before; 
the  machinery  for  making  shoes  has  so  increased  the 
demand  for  shoes  as  to  give  increased  value  to  hides, 
or  an  equal  value  to  more  of  them.  Coal  tar  was  once 
an  annoying  by-product  of  gas-works,  but  is  now  a 
source  of  medicine,  beautiful  dyes,  and  perfumes; 
cotton  seed  has  become  valuable  as  the  source  of  a 
useful  oil ;  in  1860  it  was  refuse,  in  1870  a  fertilizer, 
in  1880  a  cattle  food,  in  1890  a  table  food.  Certain 
parts  of  animals  slaughtered  for  meat  were  once  annoy- 
ing waste;  now  every  part  is  utilized,  and  from  the 
former  waste  by-products  are  made  gelatine,  glue, 
brushes,  oils,  buttons,  medicine,  and  soap.  What 
was  once  useless  has  been  made  useful,  and  that  which 
had  value  has  been  given  ever  increasing  value  by 
manufacture,  so  that  the  prime  producing  industries 
of  farming,  fishing,  mining,  and  lumbering  may  be  said 
to  be  largely  supported  by  the  manufactures,  trans- 
portation being  the  connecting  and  similarly  dependent 
industry,  and  of  this  complex  organism  the  vital  organ 
is  the  power  plant,  without  which  the  operating  machin- 
ery would  be  lifeless  and  impotent. 

In  trying  to  realize  the  strides  that  have  been  made, 
which  is  the  first  step  in  the  appreciation  of  our  present 
situation,  it  will  be  helpful  to  look  at  some  pictures, 
in  addition  to  studying  the  figures  which  tell  the  story 


POWER  AND   MACHINERY 


15 


FIG.  1 


FIG.  2 


16 


POWER 


of  the  magnitude  of  industries  practically  non-existent 
before  power  became  available.  In  those  days  there 
was  nothing  but  the  water-mill  and  windmill,  such  as 
are  shown  in  Figs.  1  and  2,  and  about  all  they  did 
was  to  grind  grain,  lift  hammers,  or  blow  bellows  for 
furnaces;  boats  were  small  and  moved  by  sails,  and 


FIG.  3 


land  transportation  was  dependent  on  the  horse.  Com- 
pare these  illustrations  of  the  old  conditions  with  the 
following  illustrations  of  the  present.  The  picture 
(Fig.  3)  shows  the  exterior  of  the  New  York  Subway 
power  house,  occupying  a  whole  block,  with  a  capac- 
ity approaching  a  hundred  thousand  horse-power, 
and  filled  with  seemingly  complicated  machinery,  as 
will  be  appreciated  from  the  interior  of  one  half  shown 


POWER  AND   MACHINERY 


17 


in  Fig.  4.  This  power  station,  while  the  largest,  is 
only  one  of  hundreds  of  similar  ones  located  in  every 
city  in  the  country.  A  modern  steamship,  such  as 
the  Kaiser  Wilhelm  and  others,  would  have  been  no 


FIG.  4 

more  wonderful  or  unreal  to  the  owner  of  the  old  wind- 
mill, or  to  the  captain  of  the  small  sailing  vessel  of  those 
days  before  the  steam-engine,  than  would  a  vision  of 
heaven.  These  vessels,  some  of  them  over  seven  hun- 
dred feet  long,  carry  deep  down  below  the  water-line 
a  large  steam-power  plant,  such  as  is  shown  in  the  sec- 


18 


POWER 


tional  view  (Fig.  5),  with  nineteen  boilers,  each  seven- 
teen feet  in  diameter  and  shown  in  Fig.  6,  supplying 


FIG.  5 

steam  to  ten  engines  of  nearly  fifty  thousand  horse- 
power, the  size  of  which  is  clearly  indicated  in  Fig.  7 
by  the  man  standing  in  the  center  of  the  picture. 

No  less  impressive  is  the 
comparison  of  the  old  horse 
and  wagon  as  the  sole  de- 
pendence for  moving  goods 
on  land  with  a  modern  loco- 
motive, one  of  the  latest 
and  heaviest  of  which  for 
the  Erie  R.  R.  is  shown  in 
Fig.  8,  a  complete  steam- 
power  plant  in  itself,  ca- 
pable of  drawing  across 
the  country  half  a  hundred 
cars,  each  carrying  fifty 
tons  of  coal,  at  high  speed, 
and  another  for  the  New 
York  Central,  shown  in  Fig.  9,  which  is  capable  of 
drawing  a  heavy  ten-car  Pullman  train  over  a  mile 
a  minute,  making  possible  a  journey  to  Chicago,  of 
about  nine  hundred  miles,  in  eighteen  hours,  main- 


FIG.  6 


POWER  AND   MACHINERY 


19 


taining   an   average   speed,    including   stops   for   coal, 
water,  switch,  signals,  and  stations,  of  fifty  miles  an 


hour.  There  are  no  statistics  of  steamship  transporta- 
tion available,  but  the  railroad  business,  so  largely 
supported  by  the  manufacturing  industries,  is  fairly 


20 


POWER 


well  determined,  and  included  in  1900  a  passenger 
mileage  of  over  one  and  a  half  billion  miles,  or  over 
two  hundred  miles  per  capita  of  population,  while  the 
freight  haulage  was  equivalent  to  one  hundred  and 


FIG. 


forty-one  billion   six  hundred  million   ton  miles  (one 
ton  hauled  one  mile). 

Just  as  a  comparison  of  the  pictures  of  the  modern 
power  plants  with  the  old  wind  and  water  mills  is  use- 
ful, so  will  be  a  brief  survey  of  a  few  characteristic  estab- 
lishments of  the  larger  manufacturing  industries,  which 
did  not  exist  at  all  before  the  advent  of  the  steam  engine. 


FIG.  9 

Some  of  these  establishments  employ  hundreds  and 
even  thousands  of  men,  and  constitute,  with  the  homes 
of  the  workmen,  the  stores  and  homes  of  the  tradesmen 
who  supply  them,  fair-sized  cities  in  themselves.  The 
greatest  manufacturing  groups  are  of  food-stuffs,  iron 
and  steel  products,  and  textiles,  and  the  following 


POWER  AND   MACHINERY 


21 


pictures  of  one  establishment  of  each  class  will  serve 
the  purpose.     The  slaughter-houses,  meat-product  fac- 


FIG.  10 

tories,  and  cold-storage  warehouses  of  Swift  &  Co., 
at  Chicago,  in  which  over  ten  thousand  horse-power 
is  used,  are  shown  in  Fig.  10 ;  the  Homestead  Works 


FIG.  11 


of  the  Carnegie  Steel  Co.  at  Pittsburg  in  Fig.  11  ;   the 
machine  shop  of  the  Allis-Chalmers  Co.  at  Milwaukee 


22 


POWER 


in  Fig.  12,  and  in  Fig.  13  is  shown  the  largest  cotton 
mill  in  the  world,  located  at  New  Bedford.  This  mill 
can  house  over  five  thousand  looms  for  weaving  cloth, 


'  FIG.  12 


and  one  hundred  and  fifty  thousand  spindles  for  making 
the  necessary  thread,  all  of  which  require  some  ten 
thousand  horse-power  to  drive.  The  appearance  of  a 


FIG.  13 


spinning  room  showing  the  rows  of  spindles  on  the 
machines  is  shown  in  Fig.  14. 

In  round  numbers,  85  per  cent  of  all  the  power  last 
reported  in  use  in  this  country  for  manufacturing  is 


POWER  AND   MACHINERY 


23 


derived  from  the  combustion  of  fuel  in  steam-boilers, 
which  deliver  steam  to  engines  and  other  apparatus 
capable  of  producing  mechanical  motion,  and  in  the 
case  of  locomotives  and  steamships  nothing  but  fuel- 
burning  steam  systems  are  in  general  use.  About 
14  per  cent  of  the  power  generated  on  land  for  station- 
ary use  is  derived  from  falling  water,  and  about  1  per 


FIG.  14 

cent  from  fuel  turned  into  gas,  mixed  with  air  and 
exploded  in  gas  engines,  so  that  practically  86  per  cent 
of  the  power  in  use  on  land,  and  all  of  that  in  use  by 
railroads  and  steamships,  are  derived  from  fuel  sources, 
and  the  remainder  from  natural  streams.  Fuel  in 
some  form  is,  then,  our  principal  source  of  natural  energy 
to-day,  and  is  becoming  increasingly  our  main  depen- 
dence, as  the  percentage  of  power  derived  from  streams 
has  been  continuously  decreasing  for  forty  years. 


24  POWER 

While  the  natural  fuel  may  vary  from  hard,  glossy, 
anthracite  coal  through  various  grades  of  soft  coal 
to  spongy  peat  in  the  solid  fuel  class,  and  through 
various  oils  in  the  liquid  class  to  natural  gas,  all  can 
be  traced  to  sun-grown  plants  that  have  died  and  become 
packed  together  beneath  earth  and  rock.  The  source 
of  the  energy  of  these  fuels,  then,  seems  to  be  traceable 
in  turn  to  the  heat  of  the  sun,  which  produces  the  plant 
growth,  and  it  is  likewise  the  sun  that  evaporates 
water  from  the  ocean,  forming  clouds,  which  are  driven 
by  sun-produced  winds  over  the  cold  places,  condens- 
ing the  vapor  into  rain,  which,  falling  on  high  places, 
produces  rivers  and  waterfalls.  Fuel,  flowing  river 
water,  and  the  winds  themselves  all  owe  their  energy 
to  the  sun,  each  manifesting  its  energy  in  its  own 
peculiar  way,  and  requiring  a  corresponding  variety 
of  machines  to  enable  each  form  to  do  the  same  work 
at  will.  It  has  been  estimated  (Putnam)  that  the  rate 
of  increase  in  using  power  since  1870  has  been  such  as 
to  double  the  amount  every  ten  years,  shown  in  Fig.  15, 
and  this  same  rate  of  increase  applies  as  well  to  coal 
production,  railroad  gross  earnings,  freight  ton  mile- 
age, passenger  mileage,  and  value  of  agricultural 
products,  proving  absolutely  the  direct  relation  and 
dependence  of  the  industries  on  power,  and  how  serious 
will  be  the  effect  of  lack  of  available  power  to  meet 
the  demands  of  industrial  progress. 

Coal  is  the  main  fuel  dependence  now,  and  there  was 
produced  in  1907  about  450,000,000  tons ;  in  1906  the 
railroads  alone  used  90,000,000  tons,  for  which  was  paid 
$170,000,000.  At  the  present  rate  the  known  supply 
of  anthracite  will  be  exhausted  in  about  70  years,  but 


POWER  AND   MACHINERY 


25 


the  bituminous  supply  will  last  longer.  It  is  estimated, 
by  E.  W.  Parker,  of  the  United  States  Geological  Survey, 
that,  if  the  present  rate  of  increase  continues  for  150 


NOTALLCO 


I 

OOKCN      l_IMt  (    ESTI  MftTCD      IMCBfftSE 

m    HBIL«O«OS    SU     NOTE     PACE 


FIG.  15 


years  and  the  consumption  then  becomes  constant, 
the  supply  will  last  700  years.  Similar  estimates  place 
the  water-power  capacity  of  our  streams  at  30,000,000 


26  POWER 

h.  p.,  of  which  only  10  per  cent  is  now  used.  So  long 
as  these  natural  supplies  are  depended  upon,  great  care 
must  be  exercised  in  preventing  waste;  but  it  must  be 
remembered  that  millions  of  square  miles  of  land, 
especially  in  tropical  countries,  can  be  put  under  culti- 
vation to  produce  wood  for  fuel,  or  the  more  rapid- 
growing  substances  like  sugar-cane,  sorghum,  corn,  or  po- 
tatoes, bearing  starch  or  sugar,  which  can  be  converted 
into  alcohol  in  never  ending  supply.  Just  what  fuel 
is  to  be  used  and  by  what  system  of  machinery  now  or 
in  the  future,  and  whether  fuel  or  water-power,  will 
depend  on  the  cost  of  the  power  by  the  system,  which 
is  a  negative  measure  of  waste.  That  source  of  energy 
and  system  of  machinery  that  produces  power  with 
the  least  net  waste  is  the  one  that  will  be  used,  —  least 
waste  of  energy,  of  man's  labor,  of  wear  in  machinery, 
and  of  investment,  all  together;  and  the  prediction  of 
the  industrial  future  of  the  country,  which  in  turn  so 
powerfully  influences  its  social  and  economic  welfare, 
is  resolved  to  a  study  of  waste  reduction. 

By  making  studies  of  nature's  substances  and  na- 
ture's stores  of  energy,  and  evolving  means  of  using 
the  latter  to  do  the  work  of  transporting  the  substances 
which  are  to  be  or  have  been  changed  to  useful  forms 
by  similar  power-driven  machinery,  not  only  has  the 
wealth  of  the  country  been  enormously  increased  and 
the  general  average  of  living  likewise  been  raised,  but 
direct  employment  has  been  created  for  ever  increasing 
millions  of  population  as  wealth  producers  and  traders 
in  goods  produced.  The  success  of  industrial  under- 
takings, dependent  as  it  is  primarily  on  the  economic 
use  of  power,  is,  however,  and  always  will  be,  impossible 


POWER  AND  MACHINERY  27 

without  men,  men  of  every  walk  of  life,  every  degree  of 
physical  strength,  mental  power,  and  education.  Equal 
as  men  may  declare  themselves  to  be  before  the  law  in 
their  claim  of  a  right  to  live  without  annoyance  from 
others,  no  sane  man  can  believe  they  are  equal  in  at- 
tainments, or  that  the  attainments  of  any  one  may 
not  be  increased  by  study,  training,  and  experience. 
Were  we  all  farmers  or  all  weavers  of  cloth,  there  would 
be  no  possibility  of  finding  an  occupation  for  each, 
best  suited  to  his  ability,  but  the  creation  of  these  varied 
industries  has  had  the  effect  of  diversifying  the  duties 
of  the  army  of  men  necessary  to  conduct  their  affairs. 
There  is  now  work  to  be  done  in  infinite  variety  and  of 
different  degrees  of  difficulty,  so  that  the  most  ignorant 
man  may  find  a  useful  place  in  the  same  establishment 
with  the  one  most  richly  endowed  with  brain  power 
developed  to  the  maximum  by  education  and  experience, 
and  capable  of  directing  its  affairs,  which  are  often  more 
complicated  and  difficult  to  administer  correctly  than 
those  of  state  government. 

To  make  a  watch  requires  a  very  large  number  of 
processes  on  many  separate  pieces  of  metal ;  for  each 
process  tools  and  machine  are  devised  and  men  trained 
to  be  skilful  in  their  use;  other  men  must  buy  the 
metal  and  the  tools,  sell  the  watches  made,  keep  the 
factory  in  repair,  keep  records  of  cost,  answer  letters, 
secure  money  for  pay-rolls,  decide  how  many  watches 
of  each  style  shall  be  made,  far  in  advance  of  the  time 
they  will  really  be  wanted.  Each  man  must  work  in 
definite  relation  to  the  others  or  the  result  will  not  be 
attained ;  so  that  the  relation  of  the  men  to  each  other 
and  to  their  tools  and  machines  must  be  similar  to  the 


28  POWER 

relation  existing  between  the  parts  of  the  watch,  even 
in  spite  of  the  fact  that  each  man  is  human  and  is 
endowed  with  feelings  and  human  perversity.  The 
adjustment  of  these  human  relations  to  form  the  human 
machine,  called  the  organization,  is  just  as  necessary 
in  one  kind  of  industry  as  in  another ;  without  such 
organization  there  would  be  no  effective  or  economic 
manufacturing  or  transportation.  The  organization 
is  the  result  of  the  attempts  to  reduce  waste  of  human 
effort,  such  as  results  when  one  man  has  to  repeat  the 
work  of  another,  or  when  one  man  opposes  the  efforts 
of  another,  or  when  any  one  is  idle  or  fails  to  produce 
as  much  as  he  can.  The  systematic  study  of  reduction 
of  waste  of  labor,  by  management  and  organization 
systems,  is  a  comparatively  recent  thing,  undertaken 
only  after  years  of  effort  in  reducing  waste  of  energy 
in  power  machinery,  and  waste  of  substances  not  in 
available  form,  but  which  could  be  made  into  new  and 
useful  forms  by  persistent  trial.  That  men  properly 
organized,  trained,  assisted,  and  properly  paid  can 
produce  effects  enormously  greater  than  many  times 
the  same  number  of  unorganized  individuals,  especially 
when  assisted  by  capital,  is  a  basal  proposition  of  the 
industries,  which  we  were  as  slow  in  learning  as  we  were 
the  lesson  that  nature's  energy  might  be  made  to  do 
man's  work.  It  really  seems  as  if  the  methods  learned 
in  applying  nature's  orderly  laws  controlling  the  gen- 
eration of  power  and  its  application  to  machinery  are  to 
be  the  means  of  teaching  us  how  best  to  get  along  with 
each  other,  to  work  in  common  to  produce  desired  results 
with  the  least  waste,  as  effectively  and  harmoniously 
as  do  the  parts  of  the  press  that  prints  our  daily  papers. 


II 


MEANS   EMPLOYED    FOR   THE    SUBSTITUTION    OF   POWER 
FOR    THE    LABOR    OF   MEN 

IN  the  story  of  the  development  of  power  machinery, 
the  part  played  by  the  rods,  shafts,  cylinders,  and 
other  elements  of  the  mechanism  as  arranged  and 
rearranged,  important  as  it  is,  is  subordinate  to  the 
ideas  or  conceptions  of  the  physical  processes  that 
each  rearrangement  of  well-known  parts  is  devised  to 
carry  out. 

It  is  more  important  to  know  j  ust  how  steam  when  made 
should  be  treated  to  give  the  most  work,  than  to  make 
a  steam-engine  that  will  run ;  more  important  to  know 
how  combustible  gas  mixed  with  air  should  be  treated 
to  give  an  explosion  with  the  highest  possible  pressure, 
than  to  make  a  chamber  strong  enough  to  hold  the 
exploding  mixture  without  breaking.  Generalizing, 
it  may  be  said  that  knowledge  of  what  should  be  done 
is  more  important  and  of  higher  order  than  mere 
ability  to  make  a  mechanism  that  will  work  after  a 
fashion. 

Each  process  as  it  was  conceived  added  a  fact  to 
man's  understanding  of  physical  nature,  and  in  turn 
contributed  to  the  discovery  of  the  next.  Air  and 
water  in  motion,  being  capable  of  moving  wheels  with 
paddles,  naturally  lead  a  student  to  inquire  how  fluids, 
water,  air,  steam,  etc.,  may  be  put  in  motion,  a  question 

29 


30  POWER 

which,  once  conceived,  almost  instantly  answers  itself, 
-  by  allowing  them  to  escape  from  high-pressure  cham- 
bers. The  next  logical  step  is  to  inquire  how  fluids 
may  be  prepared  so  as  to  have  high  pressures  in  cham- 
bers from  which  they  may  escape,  and  this  leads  to 
the  discovery  that  water  may  be  boiled  in  closed  vessels 
by  fire  outside,  or  that  explosions  of  powder  and  gas- 
eous fuels  may  be  caused  to  take  place,  or,  more  simply, 
that  water  may  be  led  in  pipes  from  the  upper  level 
of  a  waterfall  to  the  lower  level;  and  at  once  the  three 
characteristic  systems  of  power  generation  are  under- 
stood, —  water-power,  steam-power,  and  gas-power 
systems.  Experience  with  high-pressure  fluid  results 
in  an  understanding  of  its  tendency  to  push  apart  the 
inclosing  walls,  one  of  which  may  be  movable  and  on 
which  the  pressure  may  alternately  act,  as  it  moves 
back  and  forth,  and  there  is  in  consequence  developed 
the  idea  of  another  way  of  securing  motion  from  fluids 
under  pressure,  besides  the  older  one  of  jets  striking 
paddle-wheels.  An  almost  infinite  number  of  com- 
binations of  mechanism  parts  and  constructive  details 
can  be  found  to  carry  out  each  process,  so  that  the 
processes  are  fundamental  and  the  mechanisms  inci- 
dental. It  must  not  be  understood,  however,  that 
these  several  parts  may  have  infinite  variety  of  form, 
or  that  they  may  be  made  of  any  convenient  material, 
for  there  are  limitations  which  must  not  be  ignored. 
The  mechanical  elements  must  have  such  simple  form 
as  to  be  easily  made  by  the  shop  tools  and  workmen; 
both  the  form  and  material  of  each  part  must  be  suit- 
able for  the  purpose  in  strength,  stiffness,  flexibility, 
or  wearing  qualities;  and  the  whole  machine  must  be 


SUBSTITUTION  OF  POWER  31 

neither  too  costly  to  produce  or  to  keep  in  repair,  nor 
require  too  skilful  an  operator  to  manage. 

The  problem  of  power-machinery  development  is, 
therefore,  divisible  into  several  parts:  First,  what 
processes  must  be  carried  out  to  produce  motion  against 
resistance  from  the  energy  of  winds,  the  water  of  the 
rivers,  or  from  fuel.  Second,  what  combinations 
of  simply  formed  parts  can  be  made  to  carry  out 
the  process  or  series  of  processes.  These  two  steps 
when  worked  out  will  result  in  some  kind  of  an  engine, 
but  it  may  not  be  a  good  engine,  for  it  may  use  up  too 
much  natural  energy  for  the  work  it  does ;  some  part 
may  break  or  another  wear  too  fast ;  some  part  may 
have  a  form  that  no  workman  can  make,  or  use  up 
too  much  material  or  time  in  the  making;  in  short, 
while  the  engine  may  work,  it  may  be  too  wasteful, 
or  do  its  work  at  too  great  a  cost  of  coal  or  water, 
attendance  in  operation,  or  investment,  or  all  these 
together.  There  must,  therefore,  be  added  several 
other  elements  to  the  problem,  as  follows :  Third, 
how  many  ways  are  there  of  making  each  part,  and 
which  is  the  cheapest,  or  what  other  form  of  part  might 
be  devised  that  would  be  cheaper  to  make,  or  what 
cheaper  material  is  there  that  would  be  equally  suitable. 
Fourth,  how  sensitive  to  care  are  all  these  parts  when 
in  operation,  and  how  much  attendance  and  repairs 
will  be  required  to  keep  the  machine  in  good  operating 
condition.  Fifth,  how  big  must  the  important  parts 
or  the  whole  machine  be  to  utilize  all  the  energy  avail- 
able, or  to  produce  the  desired  amount  of  power. 
Sixth,  how  much  force  must  each  part  of  the  mecha- 
nism sustain,  and  how  big  must  it  be  when  made  of  suit- 


32  POWER 

able  material  so  as  not  to  break.  Seventh,  how  much 
work  can  be  produced  by  the  process  for  each  unit  of 
energy  supplied. 

In  the  early  days  of  power  generation  all  these  ele- 
ments of  the  power  problem  were  not  recognized,  but 
they  were  developed  and  studied  about  in  the  order 
named,  a  fairly  satisfactory  solution  of  the  first  part 
pointing  out  the  existence  of  the  next  and  the  neces- 
sity of  studying  it,  —  the  solution  of  a  new  question 
reacting  on  the  older  so  that  new  solutions  of  it  appeared 
that  could  not  be  conceived  before.  It  may  fairly  be 
said  that  this  systematic  study  has  been  receiving 
attention  for  about  a  century  and  a  half,  but  divided 
into  periods  as  the  study  advanced  to  the  higher  stages. 
For  example,  it  was  not  until  1860  that  the  seventh 
element  of  the  problem  was  successfully  treated  for 
those  power  systems  depending  on  the  heat  given  out 
by  fuel  as  the  source  of  energy.  Although  successful 
and  commercially  valuable  steam-engines  had  been 
continuously  produced  for  a  hundred  years,  no  one 
was  able  to  calculate  exactly  how  much  of  the  heat 
in  the  steam  might  be  converted  into  work  by  a  mecha- 
nism ideally  perfect,  so  that  the  goodness  or  badness 
of  a  mechanism  could  not  be  judged  by  any  absolute 
scientific  standard,  but  only  comparatively.  One 
engine  might'  in  operation  produce  a  certain  horse-power 
with  less  coal  per  hour  than  another,  but  no  one  could 
state  positively  why,  which,  of  course,  is  the  first  step 
in  rational  improvement  of  economy;  nor  could  the 
minimum  possibilities  of  coal  consumption  for  a  system 
be  calculated,  so  that  the  comparative  value  of  com- 
peting systems  could  not  be  judged.  This  sort  of  cal- 


SUBSTITUTION   OF  POWER  33 

culation  is  now  an  every-day  affair,  which  every  engineer 
is  capable  of  carrying  out,  and  is  the  basis  of  all  modern 
designing  and  improvement.  The  fact  that  it  took 
over  a  hundred  years  after  building  useful  engines  began 
to  arrive  at  a  scientific  conception  of  the  fundamental 
processes  which  were  being  more  or  less  imperfectly 
executed  in  machines  designed  largely  by  rule  of  thumb 
is  doubly  significant  of  the  high  order  of  mental  develop- 
ment necessary  for  this  conception,  when  it  is  realized 
that  the  first  and  second  elements  of  the  problem  appear 
to  have  been  understood  to  a  degree  sufficient  to  pro- 
duce working  models  some  two  thousand  years  before, 
since  operative  machines  were  built  at  that  time,  even 
though  they  were  not  much  more  than  toys. 

The  period  of  systematic  and  scientific  power  de- 
velopment is  coincident  with  the  true  progress  of  the 
most  basal  of  the  several  branches  of  natural  philosophy, 
chemistry,  physics,  mechanics,  thermodynamics,  and 
the  theory  of  elasticity  of  materials  of  construction ; 
and  there  is  no  doubt  that  the  steam-engine  which  was 
designed  and  built  by  workmen  before  these  were  formu- 
lated attracted  the  attention  of  philosophers  who,  in 
attempting  to  explain  what  took  place  in  it,  created 
a  related  body  of  principles  by  which  future  develop- 
ment was  guided,  and  which  are  now  the  fundamental 
bases  for  the  design  of  the  future.  Those  men  who 
became  familiar  with  the  natural  sciences,  and  also  with 
the  shop  methods  of  making  machinery,  and  who 
brought  both  to  bear  on  the  problem  of  the  production 
of  machinery  for  specified  conditions,  combining  the 
special  knowledge  of  the  scientist  and  shop  mechanic, 
were  the  first  mechanical  engineers;  and  the  profession 


34  POWER 

of  mechanical  engineering,  which  is  the  term  applied 
to  this  sort  of  business,  was  created  out  of  the  efforts 
to  improve  power  systems,  so  as  to  make  them  more 
efficient  and  adapted  to  all  classes  of  service,  and  to 
render  that  service  for  the  least  cost. 

Nothing  is  more  absorbingly  interesting  than  the 
detailed  history  of  power-system  ideas,  mechanism, 
and  the  economic  production  of  both  the  machinery 
and  the  power  itself,  studied  along  with  the  parallel 
development  of  the  natural  sciences ;  but  this  is  beyond 
the  scope  of  these  lectures,  in  which  no  more  than  the 
merest  outline  can  be  attempted,  just  sufficient  to  per- 
mit of  a  little  understanding  of  modern  machinery. 

As  has  been  already  said,  one  of  the  earliest  under- 
stood ideas  applied  to  power  generation  is  that  water 

in  motion  may,  by  striking 
paddles  on  wheels,  move  them 
and  itself  lose  some  of  its 
motion,  or  that  the  energy  of 
motion  can  be  communicated 
from  one  body  to  another. 
-''''-"•''''''—''— '•'<'<•'<'.'''•'•'<'.'.'..  Qne  Of  the  earliest  kinds  of 

wheels   based  on  this   idea  is 

shown  in  Fig.  16.  The  wheel  was  hung  by  its  shaft, 
which  was  just  a  log  of  wood,  over  the  surface  of  a 
fast-moving  stream  at  such  a  height  as  would  allow 
the  paddles  to  dip  into  the  water.  This  same  funda- 
mental idea,  old  as  it  is,  is  also  one  of  the  most  modern, 
inasmuch  as  it  is  basal  to  the  largest  modern  water 
and  steam-turbines,  for  steam  is  a  fluid  that  behaves 
much  like  water.  It  must  not  be  understood  that  the 
basal  idea  consists  in  the  dipping  of  paddles  into  a 


SUBSTITUTION   OF  POWER 


35 


brook ;  this  is  a  mere  incident,  a  convenient  way  of 
carrying  out  the  real,  fundamental  principle,  which  is 
that  moving  fluids  have  energy  by  reason  of  their 
motion,  which 
energy  can  be 
imparted  to 
wheels  by  bring- 
ing the  original 
fluid  to  rest  in 
a  suitable  way. 
One  of  the 
largest  water- 
wheels  ever 
built,  and  which 
was  designed  to 
carry  out  as 
efficiently  as 
possible  this 
same  idea,  is 
shown  in  Fig. 
17,  as  it  ap- 
peared in  the 
shop  before 
shipment.  The 
size  can  be  ap- 
preciated by 
comparing  it 
with  the  men 
standing  beside 
it  and  on  top  of  it.  This  wheel  is  at  work  below  Shawin- 
egan  Falls  in  Canada,  and  develops  10,500  h.  p.,  when 
supplied  with  water  through  an  llj-foot  pipe  from  above 


FIG.  17 


36  POWER 

the  falls,  the  total  effective  drop  being  140  feet.  The 
vanes  or  curved  partitions,  equivalent  to  the  paddles, 
are  shown  attached  to  the  shaft  in  the  picture  of  the 
runner,  Fig.  18  Precisely  the  same  basal  principle 
or  controlling  idea  is  carried  out,  with  suitable  changes 
of  structural  detail,  to  adapt  the  mechanism  to  use 
steam  instead  of  water  in  the  steam  turbine,  shown  in 
Fig.  19  as  installed  in  the  Potomac  Electric  Co.  of 
Washington.  Such  machines  as  these  are  now  built 

in    sizes    approaching 
30,000  h.  p.  each. 

In  most  of  the  mod- 
ern turbines,  which  is 
the  name  applied  to  the 
most  highly  developed 
form  of  wheels  designed 
~ " '  to  rob  moving  fluids, 

rlG.   18 

like  steam  and   water 

jets,  of  their  energy  of  motion,  there  are  involved  many 
other  principles  or  ideas,  some  of  which  are  very  old 
and  some  of  recent  conception.  One  of  these,  easy  to 
understand,  is  concerned  with  the  way  in  which  the 
steam  or  water  may  be  conveniently  set  in  motion. 
Water,  led  from  an  elevated  tank  or  pond  by  pipes  to 
a  lower  level,  exerts  a  pressure  tending  to  burst  the 
pipe,  which  is  more  powerful  the  greater  the  drop  in 
level,  and  the  pressure  tends  to  make  water  flowing 
from  a  hole  or  nozzle  move  faster  the  greater  that  pres- 
sure is.  Similarly,  water,  steam,  or  air,  or  any  other 
fluid,  confined  in  a  chamber  under  pressure,  will  escape 
from  that  chamber  through  a  nozzle  in  a  jet.  which 
will  have  a  velocity  determined  by  the  pressure.  The 


SUBSTITUTION   OF  POWER 


37 


quantity  of  fluid  that  can  escape,  as  well  as  the  energy 
of  the  jet,  will  depend  on  the  size  of  the  hole  and  veloc- 
ity of  the  jet  together.  It  has  always  been  found  most 


FIG.  19 


convenient,  because  of  the  concentration  of  energy 
that  results,  to  devise  means  of  getting  the  fluid  under 
pressure,  and  then  allowing  it  to  escape  to  give  it  motion, 


38 


POWER 


instead  of  depending  on  substances  naturally  in  motion. 
These  jets  of  fluid  may  be  allowed  to  play  on  vanes  or 
paddles  in  a  great  variety  of  ways,  giving  different 
types  of  motors  all  known  by  the  class  name  of  impulse 
wheels,  several  of  which,  intended  for  water,  are  shown 
in  Fig.  20.  Some  of  these  have  one  nozzle  and  others 


FIG.  20 

many ;  the  vanes  have  different  forms  and  are  variously 
disposed  on  the  wheels.  It  required  many  years  of 
study,  experiment,  calculation,  and  comparison  to  dis- 
cover just  what  curvature  and  angle  should  be  given 
to  these  vanes  and  nozzles  to  secure  high  efficiency,  for 
while  any  such  combination  as  shown  will  run,  there  is 
only  one  best  form  for  each  kind,  and  the  determination 
of  that  best  form  is  the  principal  problem  of  the  designer 


SUBSTITUTION   OF  POWER 


39 


to-day.  To  such  perfection  has  this  work  been  carried 
that  it  is  now  possible  to  predict,  within  one  or  two 
per  cent,  how  much  of  the  fluid  energy  a  turbine  yet 
unbuilt  will  be  capable  of  transforming  into  useful 
work.  A  pure  impulse  wheel  designed  to  receive  jets 
of  steam  is  shown  in  Fig.  21,  together  with  four  nozzles 

from  which  the     r . 

steam  is  escap- 
ing, striking  the 
curved  vanes  of 
the  wheel,  and 
in  passing 
through  having 
its  direction  of 
motion  changed 
to  give  the  im- 
pulse or  push. 
A  proper  rela- 
tion exists  be- 
tween the  speed 
of  the  vanes, 
that  of  the 
steam  jet,  and 
the  angles  and 
curvature  that  will  allow  the  steam  to  leave  with  no 
velocity  at  all,  its  original  energy  of  motion  having 
been  imparted  to  the  wheel;  and  these  things  can  now 
be  determined  with  precision. 

When  the  water  issues  in  a  fast-moving  jet  from  a 
nozzle,  the  nozzle  is  pushed  backward,  just  as  a  gun 
recoils  as  its  projectile  moves  out,  and  this  principle 
of  reaction  is  used  in  both  water-wheels  and  steam- 


FIG.  21 


40 


POWER 


turbines,  either  alone  or  associated  with  the  impulse 
action.  Some  arrangements  of  mechanism  working 
on  this  principle  are  shown  in  Fig.  22.  In  the  first 
one  the  water  flows  outward  through  curved,  hollow 
arms  fixed  to  a  hollow  shaft  through  which  the  water 


FIG.  22 

is  supplied,  escaping  from  ,the  outer  edge  or  nozzle 
tangentially.  The  same  action  takes  place  but  is  less 
clearly  seen  in  the  other  forms  shown ;  the  water  is, 
however,  conducted  to  the  working  vanes  or  nozzles 
in  different  ways.  These  passages  are  more  often  a 
continuous  row  of  slots  than  single  nozzles,  for  the 
purpose  of  getting  as  much  push  as  possible  around 
the  circumference.  To  all  wheels  in  which  the  reaction 


SUBSTITUTION   OF  POWER 


41 


of  the  jet  rather  than  the  impulse  of  striking  vanes 
exerts  the  driving  force,  the  class  name  of  reaction 
wheels  is  applied. 

The  antiquity  of  the  reaction  and  impulse  principles 
is  shown  by  the  records,  in  which  it  is  said  that  one 
Hero,  200  B.C.,  or  over  two  thousand  years  ago, 
made  such  a  steam  reaction  turbine,  shown  in  Fig.  23, 
in  which  a  fantastic  water  vessel  was  heated  by  a  fire, 
making  steam  which,  flowing  up 
two  vertical  standards,  hollow, 
like  pipes,  entered  a  ball  arranged 
to  rotate  on  the  ends  of  the  stan- 
dards. From  the  ball  the  steam 
escaped  by  nozzles  tangentially, 
causing  the  ball  to  spin,  to  the 
mystification  of  the  mass  of  the 
people,  who  believed  that  some 
spirit  from  the  other  world  had 
been  brought  under  command.  A 
later,  but  nevertheless  old,  device, 
dating  from  1629  and  credited  to 
Branca,  an  Italian,  is  shown  in  Fig.  24.  This  is  a  pure 
impulse  steam-turbine,  coupled  by  toothed  gearing  to 
a  shaft  with  lumps  on  it  arranged  to  lift  the  pestles 
for  crushing  corn  or  ore. 

The  simplest,  oldest,  and  at  once  the  most  modern 
ideas  for  power  generation  are,  then  :  - 

First,  moving  fluid  properly  directed  may  move 
wheels  against  resistance  when  it  strikes  vanes  suitably 
formed. 

Second,  fluid  under  pressure  may  be  made  to  acquire 
motion  simply  by  escaping. 


FIG.  23 


42 


POWER 


Third,  jets  of  fluid  escaping  from  nozzles  or  suitably 
formed  passages  in  wheels  may,  by  reaction  of  escape 
alone,  turn  those  wheels. 

To  these  principles  minute  and  painstaking  investi- 
gation, guided  by  progress  in  mathematics,  mechanics, 
physics,  and  chemistry,  which  it  no  doubt  assisted  in 


FIG.  24 

stimulating  as  well,  has  added  a  vast  body  of  principles 
of  engineering,  by  means  of  which  true  design  can  be 
carried  out,  and  turbines  be  built  of  predicted  efficiency, 
of  proper  strength  in  all  their  parts,  cheap  and  effec- 
tive for  all  local  situations. 

While  these  three  old  principles  of  conversion  of 
energy  are  all  used  in  present-day  turbine  water-wheels 
and  in  steam-turbines,  the  idea  underlying  the  more 
common  form  of  steam-engine  and  that  which  may  be 
said  to  have  caused  the  industrial  revolution  referred  to 
in  the  last  lecture,  the  engine  still  most  largely  used  on 


SUBSTITUTION   OF  POWER 


43 


steamships  and  in  factories  and  the  sole  dependence 
for  locomotives,  is  different.  It  is  this  idea  that  also 
finds  expression  in  all  our  gas,  gasolene,  and  oil  engines. 
This  idea  is  based  on  the  conception  of  fluid  pressure 
as  capable  of  exerting  a  push  on  pistons  in  cylinders. 
It  was  used,  though  not  understood,  by  the  savages, 
who  made  blow-guns,  in  which  the  hollow  bamboo 
stick  acts  as  a  cylinder  and  the  dart  as  piston ;  later 
also  in  powder-guns,  where  the  gun-barrel  is  the  cylin- 
der and  the  projectile  acts  as  piston.  If  a  close-fitting 
but  free-moving  piston 
in  such  a  cylinder  be 
fixed  to  a  rod,  and  water 
or  steam  under  pressure 
be  admitted  to  one  end 
of  the  cylinder,  the  fluid 
pressure  will  push  the 

piston  if  the  other  end  S/NGLE  ACT1N6 

of  the  cylinder  be  open,  FlG.  25 

and  so  move  the  rod. 

When  one  end  of  the  cylinder  is  open  and  the  other 
closed  for  a  working  chamber,  as  in  Fig.  25,  and  the 
closed  end  is  fitted  with  two  pipes,  one  for  supplying 
steam,  with  a  valve  or  cock  to  open  and  close  com- 
munication between  cylinder  and  supply,  and  the 
other  for  discharge,  opening  to  the  air,  the  cylinder 
is  said  to  be  single-acting.  Closing  both  ends  and 
passing  the  piston-rod  through  a  close-fitting  hole  in 
one  end  requires  the  addition  of  another  set  of  pipes 
and  valves,  and  it  is  then  called  a  double-acting  cylinder, 
shown  in  Fig.  26.  Two  single-acting  cylinders  placed 
side  by  side,  receiving  steam  from  a  boiler  through  one 


SUPPLY. 


44 


POWER 


DOUBLE.   ACTING 

FIG.  26 


valve,  are  shown  in  Fig.  27,  as  built  by  Leopold  in  1725, 

the  up  and  down  or  reciprocating  motion  of  the  two 

piston  rods  working 
water-pumps,  and  the 
whole  apparatus  be- 
comes a  steam-pump- 
ing-engine.  This  early 
steam-pump  uses  steam 
at  a  pressure  greater 
than  the  atmosphere, 
to  push  the  piston  to 

the  top  of  the  cylinder,  after  which  the  steam  supply 

is   cut   off   and   communication  with  the  air  opened, 

allowing  the  steam  to 

escape  to  the  air  as  the 

weight    of    the    piston 

forces  it  down. 

This    application    of 

the  pressure  idea  is  not 

the  oldest,  nor  was  it  as 

widely  used  in  its  own 

time  as  another  one,  in 

which  the  steam  at  a 

pressure  about  equal  to 

the  atmosphere  was 

drawn  into  a  cylinder, 

and  there  condensed  or 

converted  back  to  water 

by  cooling,  the  result-  FlG.  27 

ing  water  of  condensa- 
tion occupying  practically  no  volume  compared  with 

the  steam.     The  best  example  of  the  old  style  engine 


SUBSTITUTION  OF  POWER 


45 


using  this  idea  is  that  of  Newcomen,  Fig.  28.  This 
machine  had  a  single-acting  cylinder,  and  the  piston- 
rod  had  a  chain  running  over  the  curved  end  of  a  beam 
to  compel  the  rod  to  move  in  a  straight  line,  the  other 
end  of  the  beam  having  a  weight  sufficiently  heavy  to 
lift  the  piston,  and  draw 
into  the  cylinder  steam 
from  a  sort  of  kettle 
having  about  atmos- 
pheric pressure,  and, 
therefore,  incapable  of 
exerting  any  push  on 
the  piston,  even  when 
entering.  At  the  top 
position  of  the  piston 
the  cylinder  is  full  of 
steam  which,  having  a 
pressure  equal  to  the 
atmosphere  acting  on  FIG.  28 

the  outside  of  the  pis- 
ton, has  no  tendency  to  move  the  piston  one  way  or  the 
other.  Closing  the  steam  supply  valve  and  opening 
a  valve  in  a  water  pipe  between  an  elevated  tank  and 
the  cylinder  allows  water  to  flow  into  the  cylinder 
containing  the  steam,  which  is  thereby  condensed. 
The  pressure  at  once  falls  in  the  cylinder  to  a  value 
less  than  that  of  the  atmosphere  acting  on  the  outside 
of  the  piston,  the  lowered  pressure  being  called  a 
vacuum.  This  vacuum,  or  deficiency  of  pressure  within 
the  cylinder  below  that  of  the  atmosphere  outside,  al- 
lows the  atmosphere  to  press  down  on  the  piston, 
moving  it,  with  the  rod,  beam,  and  counterweight,  back 


46  POWER 

to  the  starting-point.  The  motion  against  resistance  is, 
therefore,  produced  solely  by  the  atmospheric  pressure. 
There  are  many  familiar  illustrations  of  this  vacuum 
and  atmospheric  pressure  action,  commonly  called 
suction;  the  ordinary  act  of  drawing  water  into  the 
mouth  in  drinking  is  a  mild  case,  the  muscular  move- 
ment of  the  cheeks  and  chest  producing  a  pressure  in 
the  mouth  slightly  less  than  that  of  the  atmosphere, 
which  forces  the  water  inward.  A  still  stronger  suc- 
tion or  vacuum  is  required  in  drinking  through  a  straw 
and  in  filling  a  syringe,  while  the  ordinary  barometer 
which  measures  the  atmospheric  pressure  is  only  a 
vertical  tube  of  mercury  dipping  into  a  cup  at  the 
bottom  with  a  vacuum  at  its  closed  top.  It  is  known 
that  the  most  perfect  vacuum  resulting  from  the  pump- 
ing out  of  a  glass  bulb  all  the  air  it  contained  will  enable 
it  to  suck  water,  as  we  say  ordinarily,  or  more  properly 
enable  the  surrounding  atmosphere  to  push  up  water 
into  it,  through  pipes  from  a  level  not  more  than  thirty- 
four  feet  below  it  at  sea  level,  which  is  equivalent  to 
a  pressure  of  14.7  pounds  on  each  square  inch  of  sur- 
face. If,  then,  water  be  led  into  a  vacuum  chamber 
with  an  open  pipe  extending  downward  thirty-three 
feet  or  more  into  water,  it  would  not  fill  the  chamber 
but  would  run  out,  keeping  the  level  always  the  same. 
This  engine  of  Newcomen,  which  was  used  first  in  1705 
and  continued  at  work  in  some  places  for  seventy  years, 
not  only  operated  primarily  on  the  vacuum,  as  engi- 
neers would  say,  or  by  atmospheric  pressure,  to  be  more 
scientific,  but  had  a  long  pipe  from  the  cylinder  to  allow 
the  injected  water  and  condensed  steam  to  escape  with- 
out assistance  and  automatically. 


SUBSTITUTION   OF  POWER 


47 


While  Newcomen  in  his  condensing  atmospheric 
engine  made  use  of  the  excess  of  atmospheric  pressure 
over  that  of  the  vacuum  produced  by  condensing  steam, 
and  Leopold  made  use  of  the  excess  of  steam  pressure 
over  atmosphere,  to  do  work  in  single-acting  engines, 
James  Watt  combined  the  two  pressure  actions,  getting 
as  a  result  a  double  effect  in  his  engine  of  1784.  This 
engine,  shown  in 
Fig.  29,  marked  the 
beginning  of  the 
building  of  steam- 
engines  using  the 
idea  of  pressure 
acting  on  a  recip- 
rocating piston, 
with  mechanism  to 
change  reciprocat- 
ing motion  into  the 
desired  rotary  mo- 
tion, always  under 
control.  In  it  were 
incorporated  ideas 
basal  to  the  modern  locomotive,  the  standard  hori- 
zontal and  vertical  engines  for  electric  light,  street  rail- 
way, and  factory  power  stations,  the  modern  pumping- 
engines  for  city  waterworks,  the  blowing-engine  for 
supplying  air  to  blast  furnaces  which  extract  iron  from 
the  ore,  and  a  host  of  others,  in  almost  infinite  variety 
of  detail  in  each  of  the  several  classes.  Each  of  these, 
while  having  the  essential  pistons  in  cylinders,  and 
cranks  to  give  the  rotary  motion,  valves  and  governors 
to  control  the  steam,  and  all  supplied  with  steam  made 


FIG.  29 


48 


POWER 


in  separate  boilers  from  the  combustion  of  fuel,  yet 
has  differences  of  structure  and  arrangement  of  parts, 
developed  as  time  showed  the  necessity,  to  adapt  the 
common  essential  elements  to  the  special  service.  Thus, 
the  locomotive  of  Fig.  30,  in  which  the  construction 
is  clear,  must  contain  all  the  elements  of  a  complete 
plant  supported  on  one  frame,  with  as  much  weight 
on  the  driving  wheels  as  possible  to  give  adhesion.  The 
whole  machine  must  be  rugged  to  stand  the  pounding 


FIG.  30 

on  the  rails,  so  all  delicate  mechanism  must  be  avoided. 
It  must  be  reversible,  so  mechanism  is  introduced  to 
shift  the  valves  by  hand  in  addition  to  their  normal 
automatic  movement,  and  so  on.  The  marine  engine, 
which  drives  the  ship,  must  be  fairly  well  balanced  and 
turn  regularly  without  jerks,  so  as  not  to  shake  the 
ship,  so  that  several  cylinders,  each  with  its  own  crank, 
are  set  side  by  side  and  the  cranks  set  at  different 
angles ;  it  must  also  have  a  light  frame,  so  as  not  to 
reduce  the  carrying  capacity  of  the  vessel.  This  con- 
struction is  well  shown  in  Fig.  31,  illustrating  the 
engines  of  the  United  States  battleship  Vermont  in  the 


SUBSTITUTION  OF  POWER 


49 


FIG.  31 


50 


POWER 


FIG.  33 


FIG.  34 


SUBSTITUTION   OF  POWER 


51 


shop  of  the  Fore  River  Ship  Building  Co.,  Fore  River, 
Massachusetts.  The  vessel  herself  is  shown  in  Fig.  32. 
Questions  of  weight  are  of  little  importance  in  station- 
ary engines  compared  with  steadiness  and  durability, 
but  sometimes  floor  space  is  valuable,  in  which  case 
a  vertical  engine  of  fairly  heavy  construction,  such  as 


FIG.  35 

shown  in  Fig.  33,  is  suitable.  These  engines  drive 
the  factory  of  Walter  Baker  Co.  at  Dorchester,  Massa- 
chusetts, by  electricity,  the  engines  themselves  driving 
electric  generators,  the  current  from  which  is  trans- 
mitted through  the  factory  to  motors  which  do  the 
work.  When  floor  space  is  not  valuable,  the  annoy- 
ance of  stair  climbing  to  reach  high  parts  that  need 


52 


POWER 


oiling  can  be  eliminated  and  horizontal  engines,  such 
as  shown  in  Fig.  34,  substituted.  The  relation  of 
engines  and  boilers  in  a  large  stationary  electric  plant, 
having  combined  vertical  and  horizontal  piston  en- 
gines, is  well  shown  in  Fig.  35,  which  is  a  cross-section 
of  the  Manhattan  Elevated  Railroad  plant,  as  originally 
built,  having  a  capacity  of  50,000  h.  p.  It  should  be 


FIG,  36 

noted  that  the  boilers  are  located  on  two  stories  to 
economize  real  estate,  which  is  valuable,  and  the  coal 
storage  bins  are  placed  just  under  the  roof.  Water 
for  the  condensers,  located  in  the  basement  of  the 
engine  room,  is  supplied  through  tunnels  leading  to 
the  river.  The  external  appearance  of  the  power  sta- 
tion is  shown  in  Fig.  36. 

Two  special  classes  of  piston  steam-engines,  one  for 
pumping   water   and   the   other   for   compressing   air, 


SUBSTITUTION   OF  POWER 


53 


and  therefore  called  pumping-engines  and  blowing- 
engines,  are  shown  in  Figs.  37  and  38.  The  former 
illustrates  one  of  five  Allis-Chalmers  pumping-engines, 
for  the  Hackensack  Water  Company  at  New  Milford, 
New  Jersey,  having  an  aggregate  capacity  of  72,000,000 


FIG.  37 

gallons  of  water  in  twenty-four  hours.  The  latter 
(Fig.  38)  is  a  blowing-engine  with  a  capacity  of  30,000 
cubic  feet  of  air  per  minute  at  30  pounds  pressure,  for 
the  furnaces  of  the  Republic  Iron  and  Steel  Co.,  and  its 
great  size  is  shown  by  comparing  it  with  the  man  at 
the  side. 


54  POWER 

To  produce  motion  of  an  engine  shaft  from  natural 
forms  of  energy,  it  has  been  shown  that  the  first  step 
is  to  so  supply  that  energy  as  to  get  some  fluid  under 
pressure,  if  it  is  not  so  originally,  and  then  to  use  that 
high-pressure  fluid  either  to  push  on  pistons  or  give 
itself  a  velocity  by  escaping  from  a  nozzle,  the  jet 
impinging  on  vanes  or  reacting  on  the  nozzle.  This 


FIG.  38 

is  true  no  matter  how  the  fluid  acquires  the  pressure. 
In  the  water-power  system  advantage  is  taken  of  rivers 
in  a  hill  country,  and  dams  are  constructed  when 
necessary  to  collect  rainfall  and  store  water  for  use  in 
dry  seasons  at  a  high  level,  and  pipes  are  connected  to 
conduct  the  water  to  a  low  level,  at  which  point  a 
pressure  supply  becomes  available.  On  the  other 
hand,  in  the  steam  system  the  pressure  is  produced 
by  burning  fuel  under  a  boiler ;  while  in  the  gas-power 
system,  not  yet  examined,  the  pressure  is  produced  by 


SUBSTITUTION   OF  POWER  55 

explosion  within  the  cylinder  itself,  and  the  action  of 
the  hot  high-pressure  gases  that  result  from  it  is  always 
by  direct  pressure  of  these  gases  on  a  piston.  Curi- 
ously enough,  however,  the  high  pressures  obtainable 
by  explosions  of  suitably  prepared  fuel  were  not  at  first 
directly  used,  but  instead  the  heat  of  the  combustion 
was  made  the  means  of  getting  the  atmospheric  pres- 
sure to  act,  just  as  the  atmospheric  steam-engine  pre- 
ceded that  using  high-pressure  steam.  In  1860  Huy- 
gens  exploded  gunpowder  in  a  cylinder  having  a  piston, 
the  hot  gases  escaping  from  the  cylinder  through  open 
valves  which  were  closed  as  soon  as  the  internal  pres- 
sure equaled  that  of  the  atmosphere ;  then  the  hot 
gases  were  cooled  and  in  cooling  lost  pressure,  producing 
a  partial  vacuum  exactly  as  did  the  condensing  of 
steam  in  Newcomen's  cylinder.  Atmospheric  pressure 
forces  the  piston  inward,  giving  motion,  from  the  com- 
bustion of  fuel  directly  without  any  steam  intervention, 
but  the  effect  is  feeble  and  no  successful  gas-engine 
would  ever  have  been  built  if  study  had  stopped  there. 
It  required  a  lot  of  time  to  connect  the  idea  of  the  com- 
mon gun,  using  high  gas  pressure  from  the  explosion 
of  solid  gunpowder  fuel,  with  the  piston  engine  idea. 
It  did  not  come  about  until  the  realization  that  com- 
bustible gases  mixed  with  air  would  produce  an  ex- 
plosion resulting  in  high  pressure,  that  could  be  used  to 
act  on  a  piston,  and  which  could  be  controlled  quite  as 
well  as  steam.  It  is  probable  that  the  old  notion  of 
explosion  being  connected  with  destruction  had  a  good 
deal  to  do  with  the  delay.  After  a  series  of  proposals 
dealing  with  explosive  gas  and  air  mixtures,  beginning 
about  1825,  there  finally  was  produced,  but  not  before 


56 


POWER 


1860,  an  operative  gas-engine,  by  Lenoir,  a  Frenchman. 
This  engine  had  a  cylinder  and  piston  with  the  usual 
rods,  cranks,  and  shafts  that  had  had  at  this  time  nearly 
a  century  of  service  in  steam-engines.  The  cylinder 
(Fig.  39)  is  fitted  with  valves  on  one  side  through  which 
the  piston  may  suck  in  air  and  gas  in  suitable  propor- 
tions, after  which  the  valve  is  closed  and  the  mixture 
ignited  by  an  electric  spark,  which  causes  an  explosion, 

the  high-pressure  gases 
from  which  drive  the 
piston  forward.  On 
the  return  stroke  the 
burnt  gases  are  pushed 
out  through  a  valve  on 
the  other  side.  The 
general  appearance  of 


the  engine  is  shown  in 
Fig.  40.  While  the 
engine  was  a  commer- 
cial failure,  it  never- 


MmiM 

PlATE 


FIG.  39 


theless  was  the  beginning  of  a  development  which  has 
resulted  in  the  production  of  the  most  economical  fuel- 
burning  power  system  the  world  has  ever  seen,  the 
prime  element  of  which  is  the  gas-engine  itself,  in  which 
suitably  prepared  gaseous  mixtures  are  exploded  directly 
in  the  working  cylinders.  The  first  large  installation 
of  gas-engines  in  this  country,  made  at  the  Lackawanna 
Steel  Co.,  consisted  of  40,000  h.  p.,  some  of  which 
drive  electric  generators,  as  shown  in  the  upper  part  of 
Fig.  41,  while  the  rest  drive  blowing  cylinders,  as  shown 
in  the  lower  half  of  the  picture. 

It  is  a  most  significant  fact  that  although  Hero  pro- 


SUBSTITUTION   OF  POWER 


57 


duced  a  rotative  steam-engine,  that  worked,  in  200  B.C., 
nearly  two  thousand  years  elapsed  before  the  first 
commercial  rotative  steam-engine  was  produced  by 
Watt,  about  1780,  and  that  after  him  the  progress  of 
about  seventy  years  in  power-system  development 
resulted  in  advances  entirely  eclipsed  by  progress  since 
that  time.  There  are  good  reasons  for  these  things, 
and  the  key  is  to  be  found,  first,  in  the  lack  of  demand  ; 
second,  in  the  lack  of  information  to  enable  makers  of 


FIG.  40 

machinery  to  meet  demand  when  it  came.  Practically 
all  the  power  machinery  produced  before  the  time  of 
Watt,  in  1780,  except  special  devices  adapted  to  pump 
water  only,  was  more  the  result  of  accident  than  of 
logical  reasoning  from  desired  results  to  means  by 
which  they  might  be  attained.  Even  after  Watt  much 
that  was  done  was  prompted  more  by  a  desire  to  do 
something  different,  a  groping  after  something  by 
trying  everything.  There  was  no  conviction  based  on 


58 


POWER 


FIG.  41 


SUBSTITUTION    OF    POWER  59 

proof  or  on  established  principles  that  the  means  were 
right  or  best.  This  was  pure  invention,  without  which, 
it  is  true,  little  progress  is  possible;  but  true  progress 
based  on  a  conception  that  the  new  thing  proposed 
must  and  will  produce  the  desired  result  in  a  truly  better 
way,  or  produce  a  new  result  superior  to  the  old  with 
no  more  wasteful  means,  becomes  possible  only  when 
there  is  available  a  body  of  facts  and  principles  related 
to  each  other.  Such  a  body  of  related  facts  and  general 
principles  constitutes  a  science,  by  means  of  which 
existing  machinery  can  be  analyzed  to  reveal  all  its 
faults  and  their  causes,  and  the  performance  of  new 
machinery  yet  unbuilt  can  be  predicted  with  reasonable 
certainty.  This  latter  proceeding  is  true  design,  with- 
out which  invention  alone  may  result  in  nothing  more 
than  interesting  toys,  but  which  when  combined  with 
invention  gives  the  engineer  whose  business  it  is  to 
do  these  things  his  command  over  nature.  The  basis 
of  engineering  design  is  knowledge  of  facts  and  prin- 
ciples, so  that  it  is  easy  to  understand  why  in  the  early 
days  of  engine  building  no  true  design  was  possible; 
for  the  machine  and  its  processes  in  operation  them- 
selves supply  the  means  for  collecting  the  necessary 
facts,  and  mental  capacity,  however  well  trained  to  the 
work,  cannot  find  the  relation  between  the  facts  until 
the  facts  themselves  are  found  by  tests  of  the  machinery 
already  built.  Once  discovered  and  classified,  these 
relations  constitute  a  body  of  principles  having  the 
force  and  dignity  of  laws  of  nature,  the  discoveries  and 
application  of  which  to  the  uses  of  men  constitute  the 
profession  of  engineering.  The  slowness  with  which  all 
this  developed  can  best  be  explained  by  lack  of  demand. 


60  POWER 

Up  to  the  time  of  Watt  nobody  seemed  to  have  any 
use  for  rotating  shafts  except  to  grind  grain  into  flour, 
and  perhaps  to  pound  a  little  ore,  or  blow  the  bellows 
of  an  iron  furnace.  The  conditions  of  living  were  very 
simple.  Most  of  the  people  lived  in  the  country,  each 
family  producing  for  itself  by  hand  labor  and  horses 
the  necessaries  of  life,  the  men  plowing  and  reaping, 
the  women  spinning  thread  from  the  wool  of  sheep 
raised  on  the  farm,  and  both  men  and  women  weaving 
thread  into  cloth  for  their  own  clothing  during  the 
winter  months.  Simple  tools  were  used,  such  as  the 
hoe,  flail,  plow,  spinning-wheel,  and  hand  loom,  but 
there  were  some  elementary  machines,  such  as  the  stones 
for  grinding  or  polishing,  driven  by  simple  and  small 
windmills  and  water-wheels,  or  by  horses. 

There  were  no  large  cities,  but  a  good  many  villages, 
which  developed  principally  at  seaports  or  on  rivers 
where  sailing  vessels  called  and  where,  as  a  consequence, 
the  commercial  and  trading  elements  of  the  population 
congregated.  Inland  towns  were  principally  head- 
quarters for  the  wagon  and  stage-coach,  or  trading 
centers,  the  location  of  the  markets  or  fairs  where,  at 
stated  intervals,  farmers  exchanged  those  things  of 
which  they  produced  more  than  they  needed  with 
others  within  driving  distance  who  produced  other 
articles  in  like  excess.  There  was  also  a  regular  travel 
to  and  from  the  mills,  located  principally  on  river  dams 
or  at  falls,  and  these  were  the  nearest  approach  to  power 
manufacturing  as  we  understand  it.  There  was,  how- 
ever, some  other  manufacturing,  mainly  of  the  concen- 
trated hand  craft  or  trade  order,  such  as  would  result 
when  one  man  would  buy  wool,  employ  a  number  of 


SUBSTITUTION   OF   POWER  61 

hand  spinners,  and  sell  yarn  and  thread,  or  buy  these 
and  by  more  or  less  regularly  employed  weavers  make 
cloth  to  sell. 

The  most  important  manufacture,  such  as  it  was, 
was  of  woolens,  and  these  constituted  one-quarter  of  the 
total  export  of  England.  Next  to  woolens  were  iron 
and  iron  goods,  which  employed  in  all  their  branches 
about  two  hundred  thousand  persons.  There  were 
also  some  pottery,  hardware,  and  cutlery,  and  about 
thirty  thousand  people  engaged  in  making  brass  and 
copper  things,  also  a  little  silk,  hosiery,  and  glass,  all 
produced  without  power. 

It  was  not  until  after  a  series  of  inventions  in  spinning 
and  weaving  resulted  in  machines  that  required  power 
that  the  change  of  conditions  began.  This  series  of 
inventions  began  in  about  1738,  when  Kay  invented 
the  fly-shuttle,  to  carry  the  thread  across  and  back  in 
weaving,  and  enabled  one  hand  weaver  to  do  the  work 
of  two,  thus  doubling  the  demand  of  weavers  for  thread 
and  stimulating  the  spinners  to  catch  up.  Then  Har- 
greaves  made  a  spinning  machine  that  increased  eight 
times  the  capacity  of  the  spinner,  thus  producing  more 
thread  than  the  weavers  could  use,  which  was  followed 
by  future  improvements  in  spinning  by  Arkwright  in 
1768  and  Crompton  in  1779,  just  about  Watt's  time. 
This  great  advance  in  spinning  by  machinery  was  all 
the  stimulus  needed  to  similarly  develop  the  power 
loom,  perfected  by  Dr.  Cartwright  in  1787,  when  Watt 
was  building  steam-engines  for  sale.  These  Watt 
engines  were  put  into  textile  factories,  which  could 
be  located  wherever  most  convenient  to  supplies  of 
coal,  or  raw  material,  and  were  not  limited  to  waterfalls 


62  POWER 

on  rivers.  Thus  it  was  demonstrated  that  power  could 
be  produced  from  coal  and  cheaper  than  in  any  other 
way,  and  could  successfully  operate  manufacturing 
machinery  in  factories.  The  power  machinery  worked 
reliably  and  well,  maintaining  the  regular,  steady  speed 
needed  to  prevent  the  breaking  of  fine  threads,  and 
directed  the  attention  of  everybody  to  devising  other 
ways  of  doing  their  work,  or  making  things  by  machin- 
ery, that  would  permit  the  use  of  these  engines.  One 
of  the  most  important  industries  to  which  power  machin- 
ery greatly  contributed,  and  curiously  enough  one  on 
which  it  was  also  very  largely  dependent,  was  the  iron 
industry.  By  machinery  ore,  limestone,  and  fuel  are 
supplied  to  tall  furnaces  and  air  blown  in,  originally 
from  bellows;  the  steam-engine  was  applied  to  Smea- 
ton's  cylinder  blower  within  ten  years ;  while  a  few 
years  before,  the  plan  of  driving  large  cold  iron  rollers 
by  the  engine,  to  squeeze  lumps  of  red-hot  iron  into 
bars  of  useful  shapes  and  improving  the  toughness  of 
the  metal,  had  been  adopted,  thus  improving  the  quality 
of  metal  with  which  to  build  machines,  greatly  increasing 
the  output  to  meet  the  new  demand,  and  at  once  cheap- 
ening the  product.  These  cases  are  cited  merely  as 
illustrations  of  the  almost  immediate  world-wide  in- 
terest in  machinery  of  all  kinds  to  use  power. 

It  is  impossible  here  to  examine  all  the  modifications 
of  power  apparatus  adapted  to  various  applications, 
but  it  is  most  interesting  and  instructive  to  notice  how 
slow  men's  minds  work  with  new  ideas,  as  demonstrated 
by  the  long  time  it  took  to  take,  what  now  seems 
obvious,  the  steps  of  applying  Watt's  successful  engine 
to  locomotives  and  steamboats.  Although  the  Romans 


SUBSTITUTION  OF  POWER 


63 


are  reported  to  have  used  paddle-wheel  boats  driven 
by  horses  and  oxen,  yet  it  was  not  until  twenty-seven 
years  after  Watt's  steam-engine  that  Fulton  produced 
the  first  commercially  successful  steamboat,  using  an 
engine  that  he  bought  complete  from  Watt ;  and  not 
until  1829,  about  fifty  years  after  Watt,  that  Stephen- 
son  produced  the  first  commercially  successful  loco- 
motive, "The  Rocket."  These  long  lapses  of  time 
for  so  simple  a 
thing  as  the 
adaptation  of  a 
successful  rota- 
t  i  v  e  steam- 
engine  to  the 
moving  of  the 
paddles  of  a 
steamboat,  and 
to  driving  the 
wheels  of  a  loco- 
motive, are  most 
significant,  and  FlG  42 

doubly  so  when 

it  is  remembered  that  both  the  Clermont  and  the 
"Rocket"  were  built  on  the  collective  ideas  of  many 
preceding  years  of  trial.  Even  these  two  productions, 
Stephenson's  locomotive,  the  "Rocket,"  and  Fulton's 
steamboat,  the  Clermont,  were  extremely  crude  affairs, 
as  will  appear  on  comparing  Fig.  42,  the  "Rocket," 
with  the  modern  locomotive  that  we  know,  and  by 
comparing  Fulton's  Clermont  (Fig.  43)  with  the  modern 
river-  and  ocean-going  boats  (Fig.  44). 

No  one  can  fail  to  be  impressed  with  the  enormous 


64 


POWER 


differences  between  the  old  and  the  new  power  machin- 
ery, but  this  comparison  cannot  begin  to  teach  a  lesson 
of  value  anywhere  near  proportional  to  that  which 

follows  a  study 
of  the  ideas  un- 

i"T\  '^^^      k  derlying  the 

\    I  '  JP^Bi  KJi  change,  or  their 

V  I     '-  S4^  M*  1^*3       ^?&L-  ^        ultimate  conse- 
•  -*-  quences.      The 

machines,  as 
assemblages  of 
working  parts, 
each  with  duties 


FIG.  43 


to  perform,  are 
but  the  outward 
and  visible  sign  of  principles  discovered  and  classified 
into  a  body  of  science  that  can  never  change  except 
by  additions,  and  which  is  the  inheritance  of  our 
children,  who 
may  come  to 
realize  the  po- 
tency of  these 
invisible  tools 
by  studying  the 
industrial,  so- 
cial, and  eco- 
nomic results 
that  have  fol- 
lowed their  use 

in  the  past.  Great  as  have  been  the  consequences  of 
the  use  of  power  and  machinery,  still  greater,  though 
less  easily  grasped,  is  the  contribution  to  the  develop- 


FIG.  44 


SUBSTITUTION   OF  POWER  65 

ment  of  the  natural  sciences,  which  are  to-day  so 
firmly  established  on  unassailable  foundations  that 
future  development  will  have  a  guide  as  trustworthy 
as  the  compass  to  the  ship,  pointing  out  clearly  and 
positively  the  place  where  effort  is  to  be  exerted,  in 
striking  contrast  to  the  methods  of  blind  groping  and 
wild  guessing  that  characterized  these  early  stages 
which,  even  so,  were  able  to  precipitate  an  industrial 
revolution.  Mathematics,  mechanics,  physics,  and 
chemistry  have  become  what  they  are  in  this  inter- 
mediate period.  The  laws  governing  the  strength  and 
formation  of  structures  have  been  discovered  and 
codified  in  the  modern  theory  of  elasticity  applied  to 
the  materials  of  construction.  The  nature  of  heat  and 
its  relation  to  work  were  found  out  only  toward  the 
end  of  the  period ;  but  the  basal  conception,  once 
reached,  soon  grew  and  produced  others,  until  there 
appeared  that  body  of  principles  called  Thermodynam- 
ics, inclusive  of  all  forms  of  energy,  showing  not  only 
the  essential  equivalence  of  heat,  work,  light,  electricity, 
and  magnetism,  but  also  revealing  the  laws  governing 
the  conversion  of  one  form  into  another. 

Applications  of  these  sciences,  assisted  by  the  modern 
methods  of  producing  suitable  materials  and  working 
them  into  appropriate  shapes  by  the  tools  and  systems 
now  prevailing  in  our  shops,  are  daily  producing  results 
as  wonderful  as  anything  that  Watt,  Stephenson,  or 
Fulton  ever  did.  But  as  these  productions  are  daily 
occurrences  and  not  easily  understood  by  the  mass  of 
the  people,  the  names  of  these  men  working  out  of 
sight  in  shops  and  factories  will  probably  never  be 
handed  down  to  posterity. 


Ill 

ESSENTIAL   ELEMENTS   OF   STEAM-POWER   SYSTEMS 

ALL  steam-power  systems,  whether  designed  for  land 
or  marine  transportation  or  the  stationary  generation 
of  power  contain  the  same  essential  or  primary  elements 
for  obtaining  motion  from  steam  under  pressure.  But 
besides  these  essential  elements  there  are  hundreds, 
yes,  even  thousands,  of  other  parts,  each  put  in  place 
for  a  definite  purpose,  which  may  be  generalized  under 
the  heading  of  better  or  more  efficient  service  under 
some  special  local  condition.  Even  the  essential 
elements,  similar  as  they  are,  do  themselves  differ 
vastly  in  detail,  generally  with  good  reason,  but,  of 
course,  sometimes  without.  Because  of  the  greater  vari- 
ety and  inclusive  nature  of  the  steam-power  machinery 
designed  for  stationary  work,  principal  attention  will  be 
directed  toward  this,  but  not  so  much  for  the  pur- 
pose of  demonstrating  the  variations  in  details  as  to 
indicate  the  principles  that,  once  established,  lead  to 
these  forms,  which  are,  truly,  ideas  clothed  in  metal. 

The  essential  ements  of  a  plant  whose  purpose  is 
the  generation  of  power  from  fuel  by  the  steam  sys- 
tem are :  first,  a  steam-generating  part,  and  second, 
a  part  to  use  that  steam.  The  first  part  must  make 
as  much  steam  as  possible  with  a  pound  of  coal,  and  the 
second  must  do  as  much  work  as  possible  with  a  pound 
of  steam.  The  steam-generating  equipment  will  con- 

66 


ELEMENTS  OF  STEAM-POWER  67 

sist  of  a  boiler  with  means  for  feeding  it  with  water  and 
supplying  it  with  coal,  a  furnace  adapted  to  burn  that 
coal,  a  flue  to  carry  off  the  gases  of  combustion,  con- 
taining a  damper  to  regulate  the  fire,  and  hence  the 
rate  of  steam  making,  and  means  for  creating  the  draft 
by  which  the  furnace  is  supplied  with  air,  together 
with  certain  other  trimmings  or  accessories  such  as 
glass  tubes  for  showing  the  water-level,  safety-valves 
for  preventing  the  pressure  rising  too  high,  and  con- 
nections for  removing  sediment  that  may  collect.  The 
steam-using  equipment  will  include  the  engine  proper 
and  means  for  conducting  the  steam  by  piping  from 
boiler  to  engine  and  from  engine  to  the  air,  or  condenser 
if  one  is  used.  These  piping  systems  are  oftentimes 
extremely  complicated,  especially  when  many  engines 
and  many  boilers  are  connected  together  and  these 
are  located  on  different  floors  of  the  same  building. 
In  some  plants  there  are  as  many  as  sixty  large  boilers 
under  one  roof.  The  engine  proper  consists  essentially 
of  either  a  piston  and  cylinder  with  valves  to  admit 
and  exhaust  the  steam,  or  nozzles  and  vane  wheels,  to- 
gether with  mechanism  to  regulate  speed,  lubricate 
bearings,  permit  of  adjustment  of  wearing  parts,  and 
prevent  the  leaking  of  steam  from  joints.  For  station- 
ary purposes  alone  there  are  available  to-day  on  the 
American  market  hundreds  of  different  boilers,  and 
hundreds  of  different  engines,  even  of  the  same  size, 
and  a  great  range  of  sizes,  from  a  fraction  of  a  horse- 
power up  to  approximately  thirty  thousand.  These 
large  engines  are  confined  to  the  largest  plants,  are  sel- 
dom used  singly,  and  are  always  supplied  by  a  larger 
number  of  boilers,  that  have  a  horse-power  capacity 


68  POWER 

seldom  exceeding  500  and  in  a  few  cases  1000  h.  p. 
each,  so  that  in  the  large  power  stations  one  may  expect 
a  few  large  engines  and  a  great  many  small  boilers. 
It  has  been  found  by  experience  that  the  larger  a  steam- 
engine,  other  things  being  equal,  the  less  steam  it  will 
consume  in  an  hour  to  maintain  the  horse-power.  This 
is  the  reason  why  a  few  large  engines  in  places  where 
there  is  a  great  demand  for  power  have  supplanted 
a  larger  number  of  smaller  ones.  But  this  concentra- 
tion to  get  better  steam  economy  cannot  be  carried 
too  far,  because  any  engine  unless  it  is  working  some- 
where near  its  capacity  is  wasteful  of  steam,  and  at 
certain  times  of  the  day  or  certain  seasons  of  the  year 
the  demand  for  power  is  less  than  at  other  times. 

If  there  were  just  one  engine  in  a  large  power  station, 
it  would  be  wasteful  of  steam  during  the  time  of  smaller 
demand,  however  economical  it  might  be  during  those 
times  when  the  demand  is  about  equal  to  that  for  which 
it  was  designed.  On  the  contrary,  with  boilers  there 
appears  to  be  little  change  in  the  economy  of  the  differ- 
ent sizes,  and  it  is  more  convenient  to  fit  into  available 
spaces  and  to  maintain  many  small  boilers  than  a 
few  large  ones. 

The  controlling  idea  not  only  in  plant  construction 
and  operation,  but  in  the  selection  and  form  of  every 
single  part,  is  in  every  case  economy  —  economy  not 
only  of  coal  alone,  but  of  everything  taken  together, 
each  at  its  proper  value,  not  forgetting  suitable  service; 
and  curiously  enough  it  appears  that  some  of  these 
conditions  are  contradictory.  For  example,  if  space 
be  valuable,  as  it  is  in  torpedo  boats,  the  boiler  must 
be  made  light,  and  then  it  is  difficult  to  make  it  econom- 


ELEMENTS  OF  STEAM-POWER 


69 


ical.  Similarly,  if  the  engine  must  be  highly  economi- 
cal, it  will  invariably  cost  more  to  make  than  one  less 
economical.  When  the  service  is  to  be  temporary  only, 
a  small  first  cost  is  warranted.  When  labor  is  diffi- 
cult to  secure  or  the  place  of  operation  dirty,  then  there 
must  be  a  minimum  of  complication  and  no  delicate 
parts ;  when  fuel  is  expensive,  then  the  investment 
for  machines  may  be  properly  high  if  coal  can  be  saved 
thereby,  but  the  apparatus  may  become  complicated 
and  require  much  skilled  attention,  the  cost  of  which 
may  overbalance  the  coal  saved.  These  different 
conditions  and  many  others  not  noted  have  contributed 
to  the  development  of  the  variety  of  form  in  engines, 
boilers,  and  auxiliary  equipment  now  in  existence. 
Every  separate  case  of  power  requirement  must  be 
studied  to  find  the  controlling  condition,  which,  when 
satisfied,  would  yield  the  power  with  the  least  all-round 
cost;  and  the  determination  of  this  is  a  problem  more 
difficult  to  solve  than  that 
which  Watt  had  to  meet 
when  he  tried  to  produce 
the  first  rotative  steam- 
engine. 

The  general  relations  of 
the  boiler  to  the  supply 
and  delivery  of  the  neces- 
sary substances  are  shown 
in  Fig.  45.  It  is  supplied 
with  three  things,  —  coal 
and  water  and,  of  course, 

air;  and  discharges  three  things,  —  ashes,  which  must 
be  removed,  hot  gases,  which  go  generally  to  a  stack 


COAL 


-ASHE! 


BOILER 

_  HOT 

STACK 

GASES 

FIG.  45 


70 


POWER 


or  chimney,  and  live  steam  or  steam  under  high  pres- 
sure, which  goes  to  the  engine,  and  to  the  various 
pumps  and  auxiliary  appliances,  not  shown. 

It  would  seem  that  there  should  be  no  difficulty  in 
constructing  a  vessel  in  which  to  boil  water  to  make 
steam,  and  yet  there  is  no  more  difficult  problem  for 
the  engineer  to  solve,  when  there  is  added  the  condition 


FIG.  46 


that  the  boiler  must  be  as  economical,  as  small,  or  as 
durable  as  possible,  and  otherwise  adapted  to  the  multi- 
tude of  different  conditions  under  which  it  has  to  work. 
Consider  a  plain  tank,  as  shown  in  Fig.  46,  at  the  upper 
left,  with  heat  applied  to  the  center  of  the  bottom. 
The  water  heated  immediately  over  the  fire  rises  partly 
because  it  is  a  little  lighter  than  the  rest  of  the  water 
and  partly  by  reason  of  the  steam  bubbles ;  the  rest,  or 


ELEMENTS  OF  STEAM-POWER  71 

colder  water,  will  come  down  around  the  sides.  This 
movement  of  water  is  called  convection,  and  indicates 
that  whenever  a  mass  of  water  is  unequally  heated 
there  will  be  currents  set  up.  These  currents  in  boilers 
give  what  is  known  as  circulation,  or  an  automatic 
flow  from  one  part  of  the  chamber  to  another,  and 
boilers  are  designed  so  as  to  promote  and  make  use 
of  this  circulation,  and  care  is  exercised  in  fixing  the 
form  of  boiler  and  the  location  of  the  fire  to  avoid  any 
interference  with  it.  The  next  form  of  vessel,  which 
has  an  open  tube  submerged  in  the  water,  will  permit 
of  more  violent  boiling  with  less  surface  agitation 
because  the  currents  are  guided  by  the  central  tube. 
In  the  third,  fourth,  and  fifth  forms  shown,  there  is  a 
U-shaped  tube  element  in  which  water  is  heated  more 
on  one  side  than  the  other.  It  will  rise  in  that  side  and 
fall  in  the  other,  but  may  be  made  to  flow  either  way 
by  changes  in  the  point  of  application  of  the  heat. 
When,  however,  the  construction  is  such  as  is  shown 
last,  the  water  can  flow  only  one  way  because  the  top 
of  the  circulation  tube  is  above  the  water-level.  Recog- 
nition of  these  principles  of  circulation,  the  discovery 
of  which  took  a  long  time  in  the  boiler  development, 
is  now  considered  quite  essential  to  the  making  of  good 
boilers  of  small  size  yet  capable  of  yielding  great  quan- 
tities of  steam  without  moisture.  The  earliest  boilers 
were  just  plain  tanks  set  over  grates,  with  flues  running 
under  them  and  along  the  sides,  so  as  to  keep  the  hot 
gases  in  contact  with  the  shell  long  enough  for  them 
to  give  up  their  heat  to  the  water.  It  did  not  take 
long  to  discover  that  in  order  to  make  very  much  steam 
the  tanks  would  have  to  be  pretty  large,  and  there  are 


72 


POWER 


cases  reported  in  which  these  tank  boilers  were  40  feet 
or  50  feet  long  for  only  a  few  hundred  horse-power,  a 
condition  quite  impossible  when  the  cost  of  making 
them  is  considered,  together  with  the  floor  space  they 
would  occupy.  To  reduce  the  size  and  still  present 


FIG.  47 

enough  surface  of  contact  to  the  hot  gases,  large  tubes, 
or  flues  as  they  were  called,  were  introduced  into  plain 
shells,  and  all  sorts  of  queer  shapes  of  shells  tried,  some 
of  which  are  shown  in  Fig.  47.  The  use  of  high  pres- 
sures, necessary  for  economical  use  of  steam  in  engines, 
forbids  irregular  forms  of  shells,  as  they  burst  too  easily, 
so  that  from  the  time  high  pressures  came  into  use  we 


ELEMENTS  OF  STEAM-POWER 


73 


find  nothing  but  cylindrical  shells  with  flues  or  tubes. 
One  of  the  early  flue  boilers  with  its  brick  setting  is 
shown  in  Fig.  48.  In  this  form  the  grate  is  under  one 
end,  and  the  gases  having  passed  down  under  the  boiler 
return  to  the  front  again  through  the  flue.  In  an- 
other case,  however,  fire  is  made  to  pass  in  the  flues 
down  through  the  center,  discharging  back  along  the 
sides.  Modification  of  these  flues  by  reduction  of  the 
diameter  makes 
them  tubes  and 
very  materially 
increases  the 
heating  surface 
and  steaming 
capacity  for  the 
same  size  shell, 
and  such  a  con- 
struction constitutes  the  modern  horizontal  return 
tubular  boiler,  which  is  to-day  the  most  widely  used 
type  of  stationary  boiler.  This  boiler  consists  of  a 
plain,  cylindrical  shell,  much  the  same  as  shown  in 
Fig.  48,  but  with  many  tubes  two  to  four  inches  in 
diameter  packed  in  its  lower  part,  through  which  the 
hot  gases  return  to  the  front,  after  having  passed 
from  front  to  back  under  the  bottom.  Shell  and 
grate  are  built  in  brickwork  settings.  It  has  been 
found  necessary  in  marine  service  to  avoid  brick 
settings,  and  this  condition  is  met  by  using  in  the 
lower  half  of  the  boilers  large  flues  containing  the  fire, 
the  gases  passing  to  the  back  and  returning  through 
a  bank  of  tubes  in  the  upper  part  of  the  shell,  and  this 
construction  is  that  of  the  so-called  Scotch  boiler,  as 


FIG.  48 


74 


POWER 


shown  in  Fig.  49,  the  most  widely  used  boiler  on  steam- 
ships. It  should  be  noted  how  all  flat  surfaces  on  which 
the  pressure  acts  are  braced  to  prevent  bulging.  A 


oooooooooo 

oooooooooo 

ooooooooooo 

00000000000 

oooooooooocff 

OQOOOOOO 
0000000 

oooooo 


FIG.  49 


sort  of  intermediate  type  of  boiler,  adapted  for  loco- 
motives, is  shown  in  Fig.  50,  in  which  one  end  of  the 
boiler  is  made  square,  to  form  a  fire-box  of  metal  plates 
surrounded  by  water ;  from  the  fire-box  the  gases  pass 


n 


FIG.  50 


through  straight  tubes  to  the  stack  in  front.  With 
minor  modifications  this  is  almost  the  universally  used 
type  for  locomotives,  its  form  being  well  adapted  to 
fit  on  the  frame  above  the  wheels.  In  these  three 


ELEMENTS  OF  STEAM-POWER 


75 


classes  of  boilers  shown  the  gases  pass  through  the  tubes 
and  they  are,  therefore,  known  as  fire-tube  boilers; 
and  in  some  of  them,  as  the  Scotch  marine  and  the  loco- 
motive, the  fire  is  also  within  the  boiler,  and  they  are 
said  to  be  internally  fired. 

In  all  of  these  fire-tube  boilers  the  circulation  is  not 
considered  as  effective  as  it  might  be.     In  general  the 


THf    EN*",  NTC" 


FIG.  51 


water  is  rising  from  all  the  hot  tubes,  the  steam  bubbles 
escaping  from  the  surface  of  the  water  all  over  the  center 
of  the  top.  The  water  thus  carried  up  by  the  bubbling 
forms  a  sort  of  a  hill  in  the  middle,  or  perhaps  concen- 
trated toward  one  end,  from  which  the  water  runs  down 
the  sides  of  the  shell  or  the  other  end,  back  to  the  bot- 


76  POWER 

torn,  to  supply  the  tubes  from  which  the  steam  has 
escaped.  With  a  view  largely  to  improving  the  cir- 
culation, but  for  other  reasons  as  well,  a  different  type 
of  boiler  has  been  developed,  principally  in  recent  years, 
known  as  the  water-tube  type.  In  its  horizontal  form, 
as  shown  in  Fig.  51,  it  consists  of  a  top  drum  with  two 
narrow,  flat  boxes  extending  downward  from  it,  one  at 


FIG.  52 

each  end,  and  a  bank  of  inclined  tubes  connecting  these 
approximately  vertical,  narrow  boxes,  which  are  termed 
"water  headers."  Water  rests  in  the  lower  third  of 
the  drum  and  fills  all  the  tubes  and  headers,  and  as  the 
heated  tubes  are  inclined  upward  toward  the  front,  the 
water  is  forced  to  rise  through  the  front  header,  discharge 
its  steam,  and  descend  through  the  rear  header  back 
to  the  hot  tubes.  To  insure  sufficient  activity  of  all  the 
tubes,  tiles  are  placed  between  them,  making  baffles 


ELEMENTS   OF  STEAM-POWER 


77 


which  direct  the  gases  from  the  fire  backward,  forward, 
and  finally  backward.  This  type  of  the  so-called 
horizontal  water-tube  boiler  is  built  up  of  straight  tubes, 
which  are  more  easily  cleaned  than  curved  ones.  It 
must  be  remembered  that  all  water  used  in  boilers 
contains  dissolved  salts,  which,  by  the  continuous  boil- 
ing away  of  the  water,  are  left  behind  in  a  solid  state. 


FIG.  53 

This  solid  matter  collects  in  two  ways  :  first,  as  loose 
sediment  or  mud  which  can  be  easily  blown  out;  and 
second,  as  a  hard  layer  of  stonelike  scale  sticking  to 
all  the  surface  where  the  boiling  is  taking  place  and 
interfering  with  the  flow  of  heat  through  the  tubes. 
When  tubes  are  straight,  as  they  are  in  this  boiler, 
and  holes  provided  with  cover  caps  in  the  headers, 
scrapers  can  be  run  through  them  to  knock  the  scale 
off,  an  operation  which  is  practically  impossible  with 


78 


POWER 


some  other  constructions.  Another  one  of  these 
horizontal  water-tube  boilers  is  shown  in  Fig.  52  with 
a  different  system  of  baffling.  Here,  instead  of  a  tiled 
roof  laid  over  the  bottom  row  of  tubes  directing  the 
gases  backward,  they  are  forced  to  rise  at  once,  then 
fall,  and  finally  rise,  crossing  the  tube  bank  three  times. 

In  Fig.  53  there  is  shown  a 
row  of  these  horizontal  water- 
tube  boilers  in  course  of  erec- 
tion at  the  Pacolet  Mills, 
Gainesville,  Georgia,  which 
will  serve  to  make  clear  the 
construction,  and  its  relation 
to  the  brick  inclosing  setting. 
When  there  is  plenty  of  head 
room  or  a  shortage  of  floor 
___^  space,  a  different  struc- 
ture of  boiler  may  be 
used.  To  meet  this 
condition  the  vertical 
water-tube  boiler  in  a 
variety  of  forms  has 
been  designed  and 
is  much  used,  for 
example,  by  the 
large  steel  mills,  in  which  will  be  found  dozens  of  them 
set  in  one  row.  One  of  these  vertical  boilers  is  shown 
in  Fig.  54,  consisting  of  a  bank  of  straight  tubes  between 
two  drums,  the  top  drum  having  a  hole  in  it  for  the 
discharge  of  gases,  the  whole  structure  being  surrounded 
by  brickwork ;  the  furnace,  also  of  brick,  is  separate 
and  placed  to  one  side.  A  group  of  these  boilers  in 


FIG.  54 


ELEMENTS  OF   STEAM-POWER 


79 


course  of  erection  at  the  Lowell  and  Suburban  Traction 
Company's  power  house  at  Lowell,  Massachusetts, 
is  shown  in  Fig.  55,  in  which  the  mason  building  the 
brick  walls  can  be  seen  at  work  standing  in  the  furnace 
space  and  by  whom 
the  size  of  the  struc- 
ture can  be  judged. 

There  have  also  been 
developed  a  number  of 
curved-tube  type 
boilers,  the  construc- 
tion of  which  has  been 
prompted  by  a  desire 
to  get  into  a  given 
space  as  much  tube 
surface  as  can  be  prop- 
erly arranged  in  refer- 
ence to  the  flow  of  the 
gases,  and  at  the  same 
time  promote  vigorous 
and  positive  circula- 
tion. One  of  these, 
with  the  tubes  only 

slightly  curved,  and  the  principal  curvature  given  to 
those  tubes  in  which  the  tendency  to  form  scale  is 
least,  is  shown  in  Fig.  56.  In  this  system  there  are 
three  top  drums  and  one  bottom  drum,  all  con- 
nected by  tubes  and  set  in  brickwork  with  '  baffles 
arranged  between  the  tubes  to  cause  the  gases  to  flow 
first  up  and  then  down  and  finally  up,  passing  out 
through  a  damper  to  the  flue  stack  at  the  top  of  the 
back.  This  makes  three  banks  of  tubes.  Through 


FIG.  55 


80 


POWER 


the  first  two,  water 
and  steam  together 
are  rising  under  the 
intense  heat  of  the 
fire,  and  the  water 
that  separates  out 
from  the  steam  in 
the  two  front  drums 
runs  to  the  back 
drum,  and  then 
down  through  the 
back  tubes  to  the 
bottom  drum,  re- 
turning upward 
again.  To  show 

more  clearly  the  construction  there  is  added  Fig.  57, 
showing  a  row  of  these  boilers  in  the  course  of  erection 
and  in  various  stages  of  completion  at  the  St.  Clair 
Steel  Co.,  Clairton,  Pennsylvania. 


FIG.  56 


FIG.  57 


ELEMENTS   OF  STEAM-POWER 


81 


Perhaps  the  most  severe  conditions  of  space  and  weight 
conservation  are  found  in  steamships  intended  to  go 
at  high  speeds.  Both  fire-tube  and  water-tube  boilers 
are  used ;  an  example  of  the  fire-tube  type  has  already 
been  shown  in  connection  with  the  Kaiser  Wilhelm. 
The  water-tube 
class  is  repre- 
sented by  several 
different  forms, 
some  straight 
tube  and  others 
curved  tube;  the 
curved  tube, 
however,  being 
mainly  confined  to 
torpedo  boats,  where 
the  conditions  are 
most  severe  with  re- 
gard to  space  and 
weight  limitation. 
In  every  case  these 
marine  boilers  have 
grates  underneath 
the  entire  boiler.  No 
brickwork  is  used  be- 
cause of  its  weight, 
the  boiler  being  in- 
closed by  sheet  metal  and  layers  of  non-conducting 
material.  Special  attention  is  paid  to  circulation,  and 
the  same  principles  are  followed  as  in  land  practice. 
One  special  form  that  has  been  developed  for  this 
service  is  shown  in  Fig.  58,  in  which  both  headers 


FIG.  58 


82 


POWER 


are  concentrated  at  the  front  of  the  steam  drum,  one 
as  a  box  within  the  other.  The  far  ends  of  the  tubes 
receiving  the  heat  are  closed ;  each  such  tube,  how- 
ever, has  inside  it  another  tube,  so  that  the  steam 
when  it  forms  runs  uphill  between  the  inner  and 
outer  tube  to  the  header,  together  with  some  water 
that  it  drags  along,  and  escapes  upward  through  the 
header  box,  issuing  through  a  funnel  into  the  drum. 


FIG.  59 

The  steam  and  water  here  disengage,  and  the  water 
falls  back  and  flows  down  through  the  header  again, 
but  on  the  other  side  of  a  partition,  to  the  central 
tubes,  then  along  these  to  their  open  ends,  returning 
between  inner  and  outer  tubes  to  be  again  heated. 
Boilers  of  this  water-tube  class  weigh  about  half  as 
much  per  horse-power  while  in  operation  as  those  of  the 
fire-tube  type,  and  take  up  about  half  the  space.  One 
of  the  most  concentrated  forms  of  boiler  is  that  shown 
in  Fig.  59.  The  tubes  are  bent  to  peculiar  curves, 
partly  to  secure  distribution  and  partly  to  avoid  leaks 
due  to  expansion,  and  enter  the  top  drum  above  the 


ELEMENTS   OF  STEAM-POWER  83 

water  line,  so  that  the  circulation  is  positive.  Any 
water  that  is  carried  up  in  them  descends  to  the  bot- 
tom drum  through  an  outside  large  tube,  shown  at 
the  side. 

In  addition  to  difference  in  form,  total  space  occupied, 
floor  space  occupied,  and  weight  per  horse-power,  boilers 
differ  in  cost  per  horse-power  fully  100  per  cent  between 
the  cheapest  and  the  most  expensive,  the  latter,  of  course, 
being  the  kind  that  has  the  most  hand  work  on  it,  the 
greatest  number  of  separate  parts  to  be  made  and  fitted 
together ;  the  cheapest  that  which  has  least  work  for  the 
amount  of  surface  available  for  heating.  There  are  like- 
wise some  differences  in  efficiency,  which,  in  the  case  of 
boilers,  is  measured  by  the  number  of  pounds  of  water 
that  can  be  evaporated  or  turned  into  steam  for  each 
pound  of  coal  burned,  or  the  amount  of  heat  that  can  be 
put  into  the  form  of  steam  for  each  unit  of  heat  that  the 
coal  should  liberate  on  combustion.  Strange,  indeed, 
it  is  that  enormous  variations  in  form  produce  little 
variations  in  best  efficiency  for  each,  so  that  all  these 
forms  may  be  said  to  have  about  the  same  efficiency 
if  each  is  worked  under  its  best  conditions.  These 
efficiencies  range  about  70  per  cent,  falling  to  60  and 
rising  to  80  per  cent,  with  rare  cases  beyond  these 
limits,  which  means  that  the  steam  which  leaves  the 
boiler  contains  on  the  average  about  70  per  cent  of  the 
heat  liberated  by  the  combustion  of  the  coal  in  the  fire, 
a  performance  which  is  reasonably  good,  but  which 
seems  to  be  due  more  to  the  management  of  the  fire, 
based  on  an  understanding  of  the  conditions  necessary 
for  proper  combustion  of  the  fuel,  than  to  the  design 
of  the  boiler. 


84  POWER 

There  is  scarcely  time  available  for  studying  all 
these  conditions  of  combustion,  recognition  of  which 
so  largely  controls  boiler  performance,  but  there  are 
two  important  points  in  this  connection  that  should 
be  mentioned.  In  the  first  place,  all  the  fuel  supplied 
must  be  burned,  and  any  furnace  or  fireman  that  does 
not  permit  it  all  to  be  burned  is  wasteful,  not  only  of 
the  coal,  but  also  of  time  and  of  the  investment  required 
to  build  the  boiler.  On  the  other  hand,  whatever  coal 
is  burned  requires  air  and  a  definite  amount,  different 
for  different  coals.  Combustion  is  a  chemical  com- 
bination of  coal  and  air,  and  in  all  chemical  combina- 
tions the  original  substances  combine  with  each  other 
in  a  fixed  weight  ratio.  Each  pound  of  coal,  then,  will 
require  a  definite  weight  of  air  chemically  to  combine 
with  it.  If  this  amount  of  air  is  not  supplied,  the  coal 
does  not  burn  ;  if  more  is  supplied,  it  may  burn  all  right, 
but  even  greater  harm  may  result  than  when  the  air 
is  insufficient.  The  heat  liberated  by  the  fire  will 
warm  anything  that  comes  in  contact  with  it ;  if  balls 
of  iron  were  rolled  into  the  fire  and  rolled  out  again, 
they  would  carry  away  heat  that  should  have  been 
making  steam.  If  a  stream  of  water  was  turned  into  the 
fire  and  it  was  not  too  large,  it  would  not  put  the  fire 
out,  but  it  would  rob  the  fire  of  heat  in  just  the  same 
way  as  did  the  balls  of  iron.  And  finally,  if  a  lot  of  cold 
air  is  drawn  into  the  fire,  not  needed  to  burn  the  coal, 
then  as  it  escapes  up  the  chimney  it  is  likewise  carrying 
off  some  of  the  heat  that  might  have  found  its  way  into 
the  water.  This  excess  of  air,  as  it  is  called,  has  just 
as  much  harmful  effect  on  the  efficiency  of  a  boiler  as 
a  stream  of  water  played  on  the  fire  would  have;  and 


ELEMENTS  OF  STEAM-POWER  85 

it  is  the  control  of  this  excess  of  air  that  determines 
whether  a  boiler  shall  be  efficient  or  not,  more  than  any 
other  single  thing.  The  opening  of  furnace  doors  lets 
this  air  flow  in  unchecked,  so  that  attention  must  be 
directed  toward  the  reduction  of  this  action,  and  it  is 
to  meet  this  that  mechanical  means  for  feeding  coal 
continuously  without  opening  doors  have  been  designed 
and  used.  These  will  be  referred  to  in  the  next  lecture. 

Passing  over  those  accessories  of  the  boiler  plant 
provided  merely  for  controlling  its  operation  and  its 
safety,  economizing  labor  in  handling  coal  and  ashes, 
and  conserving  waste  heat,  together  with  the  smoke- 
stacks, dampers,  pumps  for  putting  the  water  into 
the  boiler,  and  devices  to  mechanically  produce  high 
draft  to  make  coal  burn  fast,  as  well  as  the  steam 
piping  for  conveying  steam  to  the  engine,  as  elements 
of  secondary  importance,  however  essential  they  may 
be  to  the  actual  running  of  the  plant,  there  remains 
the  engine  and  its  auxiliaries  to  be  examined. 

As  already  explained,  there  are  in  use  to-day  piston 
and  turbine  engines,  and  the  characteristic  essential 
elements  of  each  are  very  simple  and  the  fundamental 
idea  easily  grasped.  Why  is  it,  then,  admitting  the 
essential  simplicity  of  the  necessary  elements,  that  some 
engines  can  be  built  highly  economical  and  others  can- 
not ?  Why  is  it  that  some  are  complicated  and  others 
simple  ?  Why  is  it  that  some  may  go  either  forwards 
or  backwards  at  will,  and  others  only  turn  one  way ; 
some  rotate  with  most  amazing  steadiness  of  motion, 
regardless  of  how  much  work  they  are  doing,  while 
others  fluctuate  in  speed  badly ;  some  are  cheap,  some 
very  expensive ;  some  capable  of  being  built  in  large 


86 


POWER 


sizes  and  others  only  in  small  ?  The  answers  to  these 
questions  appear  only  when  the  elements  of  the  engine 
which  are  non-essential  to  the  production  of  power 

are  studied  in  conjunction 
with  conditions  of  opera- 
tion. They  are  not  due 
so  much  to  reasons  under- 
lying the  securing  of  power 
from  heat  as  to  the  reasons 
underlying  the  way  in 
which  the  power  is  to  be 
generated. 

In  the  case  of  piston 
engines,  which  will  be  first 
examined,  most  of  the  dif- 
ference will  be  found  in  the 
system  of  valves  and  the 
control  of  their  motion, 
each  devised  to  meet  some 
special  condition  of  opera- 
tion newly  encountered  or 
not  previously  recognized. 
The  simplest  kind  of 
valve  for  piston  engines  is 
that  known  as  the  slide- 
valve,  which  is  a  plate  with 
a  hollow  on  one  side  or  a 
cylindrical  rod  having  a  smaller  diameter  along  the 
middle,  the  latter  form  called  a  piston-valve.  A  simple 
slide-valve  is  shown  in  Fig.  60,  in  various  positions 
in  relation  to  the  piston,  shown  only  in  part.  The 
opening  through  which  the  steam  may  flow  to  and 


&. 


$>• 


FIG.  60 


ELEMENTS  OF  STEAM-POWER  87 

from  the  cylinder  ends  appears  white,  while  the  valve 
is  lightly  shaded  and  the  metal  of  the  cylinder  is  black. 
The  valve  moves  from  side  to  side  in  a  box  or  valve 
chest,  not  shown,  but  to  which  the  steam  supply  pipe 
is  attached.  In  the  first  position  the  steam  is  entering 
the  curved  passage  or  port  to  the  left-hand  end  of  the 
cylinder,  while  from  the  other  end  of  the  cylinder 
the  piston  is  pushing  out  steam  through  the  other  port, 
then  through  the  hollow  or  the  bottom  side  of  the  valve 
into  the  irregular-shaped  space  between  the  two  ports 
which  leads  to  the  exhaust  pipe.  Movement  of  the 
piston  rotates  a  shaft,  not  shown  here,  through  rods  and 
a  crank,  and  as  this  shaft  carries  another  small  crank  of 
special  form,  attached  to  rods,  a  reciprocating  motion 
is  imparted  to  the  valve.  This  separate,  peculiar  crank 
is  called  an  eccentric,  and  it  and  the  connecting  rods 
and  valve  constitute  the  valve  gear  which  moves  the 
valve  from  one  position  to  another.  The  other  po- 
sitions of  valve  and  piston  shown  in  the  diagrams  illus- 
trate how  the  flow  of  steam  may  be  reversed  from  end 
to  end,  and  that  most  important  fact,  how  the  steam 
supply  may  be  shut  off  from  the  cylinder  before  the 
piston  reaches  the  end  of  its  stroke.  Thus  (2)  shows 
the  steam  passage  wide  open  to  the  left,  (3)  shows  it 
closed  with  the  piston  only  about  three-quarters  out, 
and  all  this  time  the  right  end  is  exhausting.  At  (4) 
the  valve  has  moved  back  enough  to  close  both  ends, 
and  they  remain  so  in  (5)  and  (6),  though  the  valve 
is  still  swinging  while  the  piston  completes  its  stroke. 
The  piston  begins  to  return  at  (7),  the  valve  has  opened 
at  the  left  to  the  exhaust,  and  is  just  about  to  admit 
fresh  steam  to  the  right.  The  remaining  positions, 


POWER 


(8)  to  (13),  illustrate  the  return  to  the  original  position. 
The  relation  of  the  slide-valve  and  its  gear  to  the  com- 
plete mechanism  of  an  engine  is  shown  in  Fig.  61,  which 


FIG.  61 


is  a  cross-section  through  the  important  parts  of  a  simple 
horizontal  engine.  Another  form  of  slide-valve,  made 
longer  and  designed  to  shorten  the  curved  passages  from 


FIG.  62 


FIG.  63 


the  valve  face  to  the  cylinder,  and  so  reduce  the  waste 
of  steam  incurred  in  filling  this  space  without  pro- 
portionate work,  is  shown  in  Fig.  62;  while  Fig.  63  is 


ELEMENTS  OF  STEAM-POWER 


89 


the  piston-form  modification  of  the  slide-valve,  which, 
being  cylindrical,  perfectly  balances  the  steam  pres- 
sure, acting  on  both  ends  instead  of  on  the  top  of  a  flat 
plate,  and  has  no  tendency  to  make  the  valve  bind  on 
the  seat  and  cause  un- 
due friction  and  wear. 
The  variation  of  form 
which  these  valves 
take,  as  well  as  the 
greater  variation  in 
the  mechanism  by 
which  their  movement 
is  controlled,  is  almost 
inconceivable  to  one 


unfamiliar    with    this 

work.  The  objects  sought  by  the  designers  of  this  most 
important  detail  of  the  engine  are  economy  and  control, 
which  are  accomplished  by  changes  of  form  of  valve 
and  its  gear,  and  are  always  tending  towards  greater 

complication  and  cost, 
the  simple  and  cheap 
kinds  being  retained 
because  there  is  always 
a  demand  for  inexpen- 
sive machines  whether 
economical  or  not.  To 
illustrate  some  of  these 
modifications  of  valve 

form  there  is  presented  a  series  of  sections  from  modern 
American  engines.  Those  of  Figs.  64,  65,  66,  and  67 
are  quite  similar  to  those  already  shown.  In  the  next 
two  (Figs.  68  and  69),  however,  there  appears  an  im- 


FIG.  65 


90 


POWER 


portant  modification ;  two  sets  of  slides,  constituting  in 
effect  four  separate  valves,  are  used,  the  pair  on  one 

side  being  for 
steam  admis- 
sion only,  while 
that  on  the 
other  side  is  for 
exhaust  only, 
so  that  the  ad- 
justment of  ex- 
haust periods 


can    be    made 

independent  of  steam  admission,  a  desirable  thing  quite 
impossible  with  a  single  valve.  In  large  engines,  which 
must  have  very  wide 
ports,  these  slide- 
valves  must  be 
given  considerable 
movement  to  get 
the  steam  passage 
open  wide  enough 
to  admit  the  neces- 
sarily great  quan- 
tity of  steam  in  a 
short  time,  and  to 
meet  this  difficulty 
a  many-slotted  or 
gridiron  construc- 
tion has  been  de- 
vised, as  shown  in 
Fig.  70,  with  twelve  slots,  so  that  full  opening  is  secured 
with  a  movement  only  one-twelfth  of  what  would  be 


FIG.  67 


ELEMENTS  OF  STEAM-POWER 


91 


necessary  with  a  single 
passage  of  the  same  total 
area,  thus  reducing  waste 
motion. 

The  exterior  view  of 
two  of  these  simple  slide- 
and  piston-valve  engines 
is  shown  in  Fig.  71,  which 
is  vertical,  and  Fig.  72, 
which  is  horizontal. 


FIG.  68 


FIG.  69 


Nearly  all  engines  of  this  class 
are  of  small  or  moder- 
ate size  and  high  speed. 
For  engines  of  larger 
size  another  type  of 
valve  and  gear  has 
been  found  better 
adapted,  as  it  tends 
to  keep  tighter  even 
when  worn,  and  wears 

less ;  it  also  permits  of  a  better  control  of  the  opening 

and  closing  pe- 
riods, both  for 

admission     and 

exhaust   steam. 

This  is   known 

as    the    Corliss 

valve,  and  like 

the    slide-valve 

it    is    made    in 

many  forms  and 

moved  in  a  great 

variety  of  ways  FIG.  70 


92 


POWER 


FIG.  71 


by  mechanism  much 
more  complicated, 
though  ever  so  much 
more  effective.  The 
Corliss  valve  proper  is 
a  cylindrical  block  of 
metal  with  one  side  cut 
away,  and  it  rotates  in 
a  round  hole  in  the 
casting  between  the 
cylinder  passage  and 
steam  supply,  or  be- 
tween cylinder  passage 
and  exhaust,  and  there 
are  always  two  valves 
for  each  end  of  the 

cylinder,  or  four  in  all.  In  Fig.  73  is  shown  a  cylinder 
in  cross-section,  with  the  four  Corliss  valves  in  various 
positions  and  the  relation  of  each  to  the  piston,  main 
crank,  and  valve  crank  or  eccentric.  Attached  to  the 
valve  at  one  end  and  projecting  through  the  casing  is 
a  small  crank 
not  shown,  by 
which  it  is  ro- 
tated through 
the  pull  of  a  rod 
derived  from  a 
system  of  rods, 
levers,  hooks, 
and  pins  from 
the  valve  cranks 
or  eccentrics  on 


FIG.  72 


ELEMENTS  OF  STEAM-POWER 


93 


the  main  shaft.  One  form  of  mechanism  to  move  these 
four  valves  is  shown  in  Fig.  74,  partly  in  section  and 
from  both  side  and  end  of  the  cylinder,  from  which  the 
complexity  of  parts  is  apparent,  but  all  of  which  are 
present  solely  to  give 
the  proper  movement 
to  the  valves  and  keep 
them  under  perfect 
control.  Other  forms 
of  the  valve  proper  and 
its  location  with  refer- 
ence to  the  cylinder  are 
shown  in  Figs  75,  76, 
77,  and  78.  The  rela- 
tion of  the  Corliss 
valve  position  to  the 
rest  of  the  engine 
mechanism  is  fairly 
well  shown  in  Fig.  79, 
which  represents  a  sec- 
tion of  a  large  vertical 
engine.  Two  exterior 
views  of  simple  Corliss 
valve  engines,  illustrat- 
ing their  varied  form 
and  the  mechanism  by  FIG  73 

which   the   valves   are 

moved  and  controlled,  are  shown  in  Figs.  80  and  81, 
which  also  indicate  the  tendency  toward  the  use  of  this 
class  of  engines  in  the  larger  sizes. 

All  of  these  various  types  of  valves,  cylinder  arrange- 
ments, and  valve  gears  have  been  prompted,  as  has 


94 


POWER 


been  said,  by  the  desire  for  better  control  of  the  steam, 
which  is  basal  to  economical  operation.  In  no  case 
can  steam  be  efficiently  used  if  it  is  allowed  to  follow 


FIG.  74 


the  piston  at  full  pressure  for  the  whole  piston  stroke. 
This  principle  was  discovered  by  Watt,  but  not  generally 
understood  in  its  fullest  significance  for  many  years. 


FIG.  75 


FIG.  76 


The  force  of  this  as  a  controlling  idea  in  steam  economy 
did  not  really  appear  until  innumerable  tests  of  steam 
consumption  had  been  made,  and  the  attempts  made 


ELEMENTS   OF  STEAM-POWER 


95 


to  explain  the  differences  found  finally  resulted  in  the 
creation  of  what  has  been  explained  as  thermodynamics. 
These  tests  and  the  thermodynamics  which  grew  out 
of  them  show  that  not 
only  must  the  differ- 
ences between  the  steam 
pressure  and  the  final 
pressure  be  as  great  as 
possible,  thus  calling  for 
the  use  of  high-pressure 
boilers  and  good  con- 
densers for  the  most 
economical  use  of  steam,  FlG  77 

but   also,  and  perhaps 

more  important,  that  the  full  use  cannot  be  made  of 
this  range  of  pressure  until  the  admission  of  the  steam 
has  been  controlled  in  a  certain  definite  way.  For 

every  range  of  pressure  from 
the  initial  to  final  there  is  a  cer- 
tain range  of  volume  through 
which  the  steam  must  pass  to 
give  the  most  results  in  work 
per  pound  of  steam.  The 
reasons  for  this  need  not  be 
gone  into  here,  as  this  would 
involve  somewhat  complicated 
mathematics,  but  a  cubic  inch 
FlG  78  of  high-pressure  steam  may  be 

imagined  as  similar  in  char- 
acter to  a  compressed  spring.  When  compressed,  this 
spring  exerts  a  certain  tension  in  the  beginning  which 
runs  down  to  something  less  at  the  end  as  the  spring 


96 


POWER 


is  released,  and  at  the  same  time  is  growing  in  size. 
It  is  evident  that  a  long  spring  much  compressed 
can  do  more  work  as  it  expands  than  a  short  spring 
lightly  compressed.  The  extension  of  the  spring  is 
somewhat  analogous  to  the  stretch  of  expansion  of  the 
steam.  The  most  work  will  be  obtained  with  the  most 
expansion  for  a  given  spring  or  for  a  given  amount 

and  kind  of  steam.  Accordingly 
only  a  little  steam  is  admitted  to 
a  cylinder.  This  little  bit  rep- 
resents the  spring  compressed. 
The  valve  is  then  closed  and  as 
the  piston  moves  out  the  steam 
expands  or  stretches,  pushing 
the  piston  throughout  the 
stroke,  as  would  the  spring  as 
it  was  released.  If  at  the  end 
of  the  stroke  the  spring  is  en- 
tirely released,  it  has  done  all 
the  work  it  can  do.  Similarly, 
with  regard  to  the  steam ;  if  at 
the  end  of  the  stroke  its  pres- 
sure has  fallen  to  that  of  the 
condenser  or  atmosphere,  it  has 
done  all  the  work  it  can  do  under  those  conditions,  and 
when  the  steam  has  done  all  the  work  it  can  do,  then 
the  most  work  has  been  obtained  per  pound  of  steam,  or 
the  greatest  economy  of  steam  results.  These  conditions 
impose  on  the  valve  and  valve  gear  a  structural  condi- 
tion, —  that  the  steam  valve  shall  open  a  little  bit  and 
then  quickly  close.  With  the  slide-valve  first  examined 
it  is  impossible  to  secure  the  admission  and  cut  off  of  the 


FIG.  79 


ELEMENTS  OF  STEAM-POWER 


97 


FIG.  80 


steam  supply  at  a  proper  time,  independent  of  the  open- 
ings and  closing  of  the  exhaust,  because  it  is  a  one-piece 
affair.  The  use  of  two  separate  slide-valves,  one  for 
exhaust  and  one  for  admission,  helps  matters  consider- 


FIG.  81 


98  POWER 

ably;  but  the  Corliss  valve  structure  permits  of  the 
greatest  possible  controlled  independence.  This  dis- 
cussion shows  that  the  first  step  in  the  economic  use 
of  steam  is  a  matter  of  mechanism  design  to  permit  of 
the  movement  of  the  valves  in  a  suitable  way,  the  suit- 
ability of  the  way  being  dictated  by  the  thermodynamic 
laws  governing  the  relations  of  heat  and  work. 

Were  there  more  time  available,  it  would  be  inter- 
esting to  trace  the  influence  of  the  character  of  service 
on  the  changes  of  form  of  engines  and  their  parts,  but 
this  would  require  a  detailed  history  of  design,  which 
would  show  that  greater  and  greater  diversity  is  enter- 
ing into  the  construction  of  engines  to  secure  the  best 
possible  adaptation  to  requirements,  contrary  to  the 
practice  of  the  early  days  when  there  was  only  one 
steam-engine  and  that  put  to  work  at  all  sorts  of  things. 

As  already  pointed  out,  the  steam-turbine  type  of 
engine  was  conceived  nearly  two  centuries  before  it 
came  into  use:  and  the  reason  is  to  be  found,  first,  in 
the  lack  of  demand;  and  second,  after  the  demand  that 
gave  Watt  his  chance  had  been  created,  then  and  for 
nearly  one  hundred  and  fifty  years,  in  the  failure  to 
understand  how  to  make  it  as  economical  as  the  piston 
engine.  Steam  can  do  the  same  work  expanding  be- 
tween the  boiler  pressure  and  that  of  the  exhaust, 
whether  it  happens  to  be  in  nozzles  or  behind  pistons, 
even  though  in  the  former  case  the  work  done  is  not 
yet  in  available  form,  but  exists  in  the  form  of  a  high- 
speed jet  of  steam.  Returning,  for  illustration,  to  the 
compressed  spring  analogy,  it  is  true  that  if  the  spring 
is  compressed  between  the  fingers  and  a  table,  it  will 
jump  up  when  released;  the  energy  of  the  compressed 


ELEMENTS  OF  STEAM-POWER  99 

spring,  measured  by  the  work  it  can  do  as  it  is  released, 
is  expended  in  giving  itself  a  velocity.  This  is  pre- 
cisely what  happens  in  the  steam  nozzle.  The  diffi- 
culty in  respect  to  economy  in  the  turbine  is,  however, 
different  from  that  in  the  piston  engine,  where  the 
problem  is  to  admit  a  small  amount  of  high-pressure 
steam  and  let  it  completely  expand  without  interfer- 
ence. There  is  no  difficulty  in  getting  complete  ex- 
pansion of  steam  in  nozzles ;  the  really  great  difficulty 
lies  in  the  relations  of  the  wheel  and  vanes  to  the  steam 
jet.  If  the  vanes  move  too  fast,  the  steam  from  the 
nozzle  may  never  catch  up,  and  so  cannot  exert  any 
push  or  do  any  work.  Similarly,  if  the  vanes  move 
too  slowly,  the  steam  jet  will  bounce  off  with  nearly 
as  much  velocity  as  it  had  before  and,  therefore,  carry 
away  nearly  all  its  original  energy.  It  appears,  then, 
that  the  vanes  must  have  a  velocity  neither  too  low 
nor  too  high,  but  definitely  related  to  the  jet  velocity 
in  order  to  secure  best  economy.  It  does  not  appear, 
however,  what  the  jet  velocity  will  be  for  any  given 
steam  pressure,  or  what  the  relation  of  the  two  veloc- 
ities should  be.  This  determination  can  be  made 
mathematically  to-day,  and  it  is  only  within  a  score  or 
so  of  years  that  it  could  be  made.  Without  this  knowl- 
edge, properly  applied,  the  steam-turbine  may  be  enor- 
mously wasteful;  for  example,  one  machine  that  was 
built  by  guess  consumed  over  a  thousand  pounds  of 
steam  per  hour  for  one  horse-power,  about  one  hundred 
times  as  much  as  a  properly  proportioned  machine 
would  use  under  the  same  conditions.  It  is  a  fact  that 
for  ordinary  pressure  conditions  the  steam  jet  will  have 
a  velocity  running  into  thousands  of  feet  per  second, 


100  POWER 

and  approximately  equal  to  that  of  a  rifle  bullet,  so 
that  to  get  suitable  velocity  relations  for  good  steam 
economy  the  vanes  must  either  rotate  too  fast  for 
safety,  or  their  speed  must  be  held  down  to  some  safe 
low  value  that  will  necessitate  waste  of  energy,  or  some 
new  means  of  treatment  must  be  devised. 

This  last  step,  the  devising  of  new  means  of  treating 
jets  and  vanes  in  turbines  to  permit  of  safe  and  other- 
wise desirably  low  speeds,  with  properly  good  economy 
in  the  use  of  steam,  will  be  taken  up  later,  together 
with  a  new  treatment  of  the  piston  engine  similar  in 
kind  and  effect  to  give  higher  economies  than  are  pos- 
sible with  the  simple  piston  machines  already  discussed. 


IV 

PRINCIPLES    OF   EFFICIENCY   IN    STEAM-POWER    SYSTEMS 

IT  has  required  far  more  effort,  and  effort  of  a  far 
higher  order,  to  make  the  steam  system  of  power  gen- 
eration as  economical  as  it  is  to-day,  than  was  required 
to  produce  the  first  successful  rotative  engine.  With- 
out the  study  of  efficiency  and  reduction  of  heat  waste 
it  is  safe  to  say  that  but  little  progress  would  have  been 
made  in  comparison  with  that  which  has  been  made. 
Even  up  to  the  year  1870,  ninety  years  after  Watt's 
successful  engine,  the  use  of  the  steam-power  system 
in  this  country  for  stationary  work  was  less  extensive 
than  the  use  of  the  water-power,  and  the  reason  is  to 
be  found  chiefly  in  the  relative  costs  of  power  by  the 
two  systems  up  to  that  time.  Although  improvements 
in  water-power  machinery  since  then  have  decreased 
its  cost  somewhat  and  have  made  it  possible  to  develop 
more  difficult  waterfalls,  and  through  electric  trans- 
mission to  increase  the  areas  over  which  water-power 
might  be  used,  yet  these  advances  are  as  nothing  com- 
pared with  the  advances  in  the  steam-power  system. 
All  advances  in  the  steam-power  system  have  come 
from  improved  shop  methods  and  from  analysis  of 
losses  through  the  methods  of  thermodynamics,  a 
science  which  itself  grew  out  of  the  earlier  engines,  which 
furnished  means  for  getting  test  data  which  thoughtful 

101 


102  POWER 

men  have  compared,  and  in  the  comparison  discovered 
the  general  laws. 

Even  with  the  best  boilers  and  engines  of  the  so- 
called  simple  type,  such  as  have  been  shown  and 
described,  the  economy  is  poor.  The  boilers  give  to 
the  steam  on  an  average  70  per  cent  of  the  heat  of  the 
fuel  or,  what  is  roughly  equivalent,  produce  10  pounds 
of  steam  per  pound  of  good  coal,  or  less  per  pound  of 
poor  coal.  The  engines,  even  of  the  better  sort,  ex- 
hausting to  the  atmosphere  use  30  or  40  pounds  of 
steam  per  hour  per  horse-power,  so  that  such  boilers 
and  engines  together  would  require  3  to  4  pounds  of 
coal  per  hour  per  horse-power,  which  amount  will  rise  in 
the  small  and  less  well-constructed  units  to  as  high  as 
6  and  8  pounds.  A  coal  consumption  of  1  pound 
per  hour  for  each  horse-power  corresponds  to  a  plant 
efficiency  of  approximately  17  per  cent ;  3  pounds  to 
about  5.6  per  cent ;  4  pounds  to  about  4.2  per  cent ; 
8  pounds  to  2.1  per  cent, — so  that  these  non-condensing 
steam  plants  with  simple  engines  burning  from  3  to 
8  pounds  of  coal  per  hour  per  horse-power,  which  is  the 
range  they  cover,  are  capable  of  converting  into  useful 
work  only  from  5  to  2  per  cent  of  the  heat  the  coal 
contains.  Improvements  in  the  apparatus  and  methods 
of  working  have  raised  this  value  to  about  15  per  cent 
in  the  best  modern  plants,  which  seem  extremely  com- 
plicated compared  with  the  simple  non-condensing 
ones.  Great  as  is  this  improvement,  the  efficiency  still 
seems  small,  but  it  is  difficult  to  realize  the  cost  of 
time,  material,  money,  and  brains  that  have  been  ex- 
pended in  making  even  this  advance. 

Such  improvements  as  have  been  made  are  of  two 


EFFICIENCY  IN   STEAM-POWER  103 

general  classes:  first,  those  belonging  strictly  to  the 
engine  to  increase  the  work  obtainable  per  pound  of 
steam;  and  second,  those  relating  to  the  efficiency  of 
steam  generation  to  increase  the  weight  of  steam  made 
per  pound  of  coal.  Most  of  those  which  have  been 
applied  to  the  generation  of  steam  have  been  directed 
toward  the  reduction  of  direct  heat  losses,  and  the 
return  to  the  boiler  water  of  some  of  the  waste  heat. 
For  example,  while  the  hot  gases  leaving  the  boiler 
must  be  hot  when  they  reach  the  chimney  to  produce 
a  proper  draft,  they  may  carry  more  heat  than  is  neces- 
sary for  the  draft,  so  that  some  heat  is  wasted.  Also 
the  exhaust  steam  from  the  engine  carries  much  heat 
away  to  be  dissipated  in  the  atmosphere,  or  given  to 
condensing  water.  If,  therefore,  the  cold  water  on  the 
way  to  the  boiler  be  brought  in  contact  with  the  exhaust 
steam  or  flue  gases,  it  will  become  warm,  and  therefore 
require  less  of  the  direct  coal  heat  to  make  it  boil. 
As  the  heat  for  boiling  the  water  is  more  and  more 
derived  from  waste  sources  and  less  from  the  coal 
directly,  the  efficiency  of  steam  generation  will  rise  and 
more  steam  will  be  made  per  pound  of  coal.  Appara- 
tus designed  to  save  waste  flue-gas  heat  is  called  an 
economizer,  and  consists  of  a  bank  of  tubes  through 
which  the  water  passes  on  its  way  to  the  boiler,  gen- 
erally set  behind  a  row  of  boilers  and  a  little  above. 
This  is  shown  in  Fig.  82,  which  represents  a  set  of  econ- 
omizers being  erected  behind  a  row  of  horizontal  in- 
clined water-tube  boilers  in  the  plant  of  the  Public 
Service  Corporation,  Newark,  New  Jersey.  To  secure 
the  advantage  of  heating  the  boiler  feed-water  by 
exhaust  steam,  an  apparatus  called  a  feed-water  heater 


104 


POWER 


is  used,  and  of  this  there  are  two  general  classes.     In 
that  shown  in  Fig.  83  the  water  passes  through  a  bank 


FIG.  82 

of  small  tubes  set  m>  a  cast-iron  casing  through  which 
the  exhaust  steam  passes.  As  there  is  no  physical 
contact  between  the  steam  and  the  water,  the  water 
remains  unchanged  except  as  its  temperature  rises. 
This  is  not  the  case  with  feed-water 
heaters  of  the  other  class,  in  which 
the  water  and  steam  mingle,  one  of 
which  is  shown  in  Fig.  84.  Here  the 
cast-iron  casing  through  which  the 
exhaust  steam  flows  is  fitted  with  a 
number  of  cast-iron  trays  over  which 
the  water  falls  and  becomes  heated. 
Steam  that  condenses,  together  with 
any  oil  that  it  may  have  carried 
/  over  from  the  engine,  falls  with  the 

r  feed-water    to    the    bottom,   where 

filtering  material  is  added  to  remove 
FIG.  83  the   oil.     These  feed-water   heaters 


EFFICIENCY  IN  STEAM-POWER 


105 


and  economizers  are  only  two  of  many  means  of 
returning  heat  waste  to  the  boiler  that  are  now  im- 
portant subjects  of  study  in  plant  economy. 

As  has  already  been  explained,  improperly  controlled 
air  supply  to  the  furnace  means  heat  waste  of  the  most 
direct  sort,  either  by 
failing  to  burn  all  the 
fuel,  when  the  air  is  in- 
sufficient, or  through 
using  more  air  than  is 
needed,  carrying  away 
to  the  chimney  too 
much  heat  in  the  form 
of  hot  gases.  Much 
work  is  being  done  to 
reduce  these  losses, 
and  in  this  part  of  the 
problem  perhaps  the 
most  important  piece 
of  apparatus  devel- 
oped is  the  mechanical  FlG  84 
stoker  and  its  furnace. 

These  stokers  are  intended  to  maintain  proper  furnace 
condition  continuously,  by  feeding  coal  mechanically 
to  furnaces  fitted  with  properly  controlled  air  openings. 
The  use  of  these  stokers  is  likewise  associated  with 
some  saving  in  labor  in  handling  the  coal,  which  is 
mechanically  elevated  from  boats  or  cars  to  bins  over 
the  boiler  room,  from  which  it  runs  down  to  each  boiler 
through  pipes.  The  elaborate  nature  of  some  of  this 
coal-handling  equipment  is  well  shown  in  Fig.  85, 
illustrating  the  river  side  of  the  New  York  Edison 


106 


POWER 


Power  Station.     Each  stoker  has  a  hopper  supplied 
with  coal  from  the  overhead  bins  by  pipes,  as  shown 


in  Fig.  86,  which  illustrates  the  fronts  of  a  row  of  boilers 
mechanically  fired  by  that  form  of  stoker  known  as 
the  chain  grate.  This  chain  grate  is  like  a  wide  belt 
of  cast-iron  links,  as  shown  in  Fig.  87,  receiving  the 

coal  at  one  end 
from  the  hopper 
and  continu- 
ously carrying 
it  back  into  the 
fire  at  a  proper 
speed,  so  that 
when  the  coal 
reaches  the  end 
there  is  nothing 
FIG.  86  but  ash  to  drop 


EFFICIENCY  IN  STEAM-POWER 


107 


off.     In  the  picture  the  stoker  is  shown  pulled  out  for 

inspection  or  repairs.     Another  form  of  stoker,   con- 

sisting of  a  set 

of  moving  bars 

on  an  incline,  is 

shown    in    Fig. 

88  in  cross-sec- 

tion,  in   which 

the  agitation  of 

the  coal  is  pos- 

sible,   a    thing 

very    desirable 

for  some  sticky 

kinds    of    coal.  „     „_ 

r  IG.   o/ 

These    illustra- 

tions tell  only  the  smallest  fractions  of  the  story  of 
attempts  to  reduce  heat  waste  and  get   more  steam 

per  pound  of  coal,  and 
will  serve  to  demon- 
strate the  nature  and 
direction  of  the  efforts. 
Their  effect  has  been 
not  so  much  the  im- 
provement of  boiler 
efficiency,  comparing 
the  best  stoker  per- 
formance with  that  of 
the  best  hand-fired 
furnace,  as  to  enable  a 
better  average  condi- 

tion to  be  maintained  than  is  possible  with  intermittent 
hand-firing,  with  all  the  variations  of  fire  condition  and 


FIG. 


108  POWER 

air  supply  entirely  subject  to  the  judgment  of  the  fire- 
man, for  the  stoker  maintains  steady  conditions  and 
reduces  the  evil  that  a  poor  fireman  may  do. 

It  is  in  the  engines  and  their  auxiliaries  that  the 
greatest  advances  have  been  made,  but  improvements 
directed  toward  the  fullest  utilization  of  the  work 
capabilities  of  steam  can  be  understood  only  when  some 
of  the  important  quantities  are  known.  It  is  these 
quantities  that  show  plainly  the  difficulties  to  be  en- 
countered in  designing  apparatus  to  carry  out  the 
processes  to  the  fullest  extent.  It  has  already  been 
explained  that  steam  will  do  all  the  work  it  is  capable 
of  doing  only  when  permitted  to  expand  or  stretch  as 
much  as  it  is  capable  of  stretching,  in  just  the  same  way 
as  a  compressed  spring  may  stretch  or  expand  to  do 
work.  It  is  important  now  to  consider  how  much 
steam,  under  the  ordinary  conditions  of  initial  and 
final  pressure  employed,  may  stretch  or  expand.  A 
boiler  pressure  of  150  pounds  per  square  inch  is  not 
considered  high  to-day,  as  pressures  going  up  to  250 
pounds  are  in  common  use;  but  even  with  the  moderate 
pressure  of  150  pounds  to  start  with,  one  pound  of 
steam  would  occupy  a  volume  of  2{  cubic  feet.  That 
is  to  say,  one  pound  of  water  when  turned  into  steam 
at  150  pounds  pressure  would  occupy  a  volume  of  2| 
cubic  feet.  If  this  steam,  which  may  be  likened  to  a 
compressed  spring,  be  allowed  to  stretch  until  its  pres- 
sure has  come  down  to  that  of  the  atmosphere,  then  it 
will  occupy  a  volume  of  23  cubic  feet,  or  it  will  have 
expanded  8.1  times,  or,  as  it  is  often  said,  it  will  have 
suffered  8.1  expansions.  If,  however,  it  be  allowed 
to  continue  to  stretch  by  the  enlargement  of  the  cham- 


EFFICIENCY  IN   STEAM-POWER  109 

ber  in  which  it  is  working,  until  its  pressure  has  fallen 
below  atmosphere  to  about  96  per  cent  of  a  perfect 
vacuum  at  sea-level,  such  as  is  obtainable  in  our  best 
modern  condensers,  then  it  would  occupy  a  volume 
of  401  cubic  feet  or  would  have  expanded  150  times 
its  original  volume.  This  means  that  one  cubic  foot 
of  steam  at  the  high  initial  pressure  of  150  pounds  per 
square  inch  becomes  150  cubic  feet  when  its  pressure 
has  been  brought  down  to  about  96  per  cent  of  a  perfect 
vacuum.  The  more  a  spring  is  allowed  to  stretch,  the 
longer  will  it  continue  to  push  against  whatever  is 
restraining  it  and  so  the  more  work  it  will  do.  Sim- 
ilarly, the  more  the  steam  is  allowed  to  stretch  or 
expand,  the  more  work  it  can  do.  It  appears,  therefore, 
that  steam  expanding  from  this  high  pressure  to  the 
vacuum  can  do  more  work  than  if  it  expanded  only  to 
the  atmosphere,  and  it  is  interesting  to  note  just  how 
much  more.  The  laws  of  thermodynamics  indicate 
that  when  expanding  from  the  high  pressure  to  atmos- 
phere, steam  can  only  do  about  54  per  cent  of  the  work 
it  could  have  done  had  it  expanded  to  the  vacuum. 
This  is  equivalent  to  saying  that  the  work  of  expansion 
from  the  high  pressure  to  the  vacuum  nearly  doubles 
the  work  it  could  do  if  the  expansion  stopped  at  the 
atmospheric  pressure.  As  a  consequence,  the  more 
complete  expansion  nearly  doubles  the  efficiency  of 
its  use  and  so  reduces  the  waste  in  its  use  to  nearly 
one-half.  This  being  the  fact,  it  appears  that  to  make 
the  best  use  of  steam  from  150  pounds  to  96  per  cent 
vacuum  in  a  piston  engine,  the  piston  should  start  at 
the  beginning  of  its  stroke  (assuming  it  to  be  working 
with  one  pound  of  steam)  with  2|  cubic  feet  of  steam 


110  POWER 

in  one  end  when  the  supply  is  cut  off,  and  the  piston 
movement  should  continue  until  the  space  within  the 
cylinder  occupied  by  the  steam  has  become  401  cubic 
feet,  or  150  times  as  much  as  it  was  in  the  beginning. 
If  this  is  done,  then  as  much  work  will  be  obtained  as 
the  steam  is  capable  of  doing,  provided  none  of  it  is 
lost  by  leakage  or  is  condensed  by  cooling  during  the 
process.  This  seems  a  simple  requirement  which,  if 
carried  out,  would  yield  a  high  efficiency  piston  engine, 
yet  as  a  matter  of  fact  it  is  absolutely  impossible  to  do 
it  at  all  in  a  single  cylinder. 

Attention  has  already  been  called  to  the  existence 
of  a  series  of  spaces  in  the  end  of  a  cylinder.  There 
is  a  steam-passage  space  between  the  valve  and  the 
cylinder,  and  another  space  between  the  end  of  the 
piston  and  the  cylinder  head  to  avoid  the  possibility 
of  the  piston  striking  the  head.  The  sum  of  these 
spaces  together  is  called  the  clearance  volume.  About 
the  smallest  clearance  volume,  that  even  the  best 
arranged  valves  will  permit,  may  be  set  at  2  per  cent 
of  the  cylinder  volume,  and  even  this  is  almost  dan- 
gerously small.  To  carry  out  such  expansion  as  has 
been  discussed,  the  volume  of  steam  at  the  beginning 
of  the  expansion  should  be  only  about  .7  of  1  per  cent 
of  the  volume  at  the  end  of  expansion,  or  less  than  the 
dead  clearance  space  itself.  If  steam  were  admitted 
to  the  cylinder  for  only  ^  of  the  stroke  of  the  piston 
and  then  cut  off,  it  could  expand  only  14  times.  If 
steam  were  admitted  only  to  fill  up  the  waste  space  and 
did  not  follow  the  piston  in  its  movement  at  all,  then 
it  might  expand  only  51  times  instead  of  the  150 
which  is  necessary  to  get  all  the  work  it  is  capable  of 


EFFICIENCY  IN   STEAM-POWER  111 

giving.  These  figures  show  the  absolute  impossibility 
of  carrying  out  this  expansion  process  in  a  single  cylin- 
der and  why  single-cylinder  or  simple  engines  are  nec- 
essarily wasteful. 

When,  however,  the  work  is  done  in  two  cylinders 
in  succession,  or  even  three  or  four,  the  conditions  are 
changed.  This  process  of  successively  working  the 
steam  in  several  cylinders  in  series,  called  multiple 
expansion,  will  permit  of  more  expansion  in  such  cylin- 
ders as  we  can  construct  than  is  possible  in  a  single 
cylinder.  Suppose,  for  example,  the  first  of  the  series 
to  be  just  large  enough  to  hold  the  pound  of  steam 
when  full,  then  if  the  largest  cylinder  have  a  volume 
150  times  this,  the  expansion  would  be  possible.  This 
would  call  for  a  low-pressure  cylinder  diameter  about 
fifteen  times  that  of  the  first  or  high-pressure  cylinder. 
These  so-called  multiple  expansion  engines  are,  there- 
fore, capable,  for  this,  as  well  as  for  some  other  reasons, 
of  making  better  use  of  the  steam  than  the  simple 
engine. 

When  several  cylinders  use  the  steam  in  succession, 
permitting  the  pressure  to  fall  in  steps  and  producing 
the  work  of  the  steam  in  stages,  the  cost  of  the  engine 
increases.  A  two-cylinder  or  compound  engine  will 
cost  about  50  per  cent  more  than  a  simple  single-cylin- 
der engine,  while  the  third  and  fourth  cylinders  for 
triple  and  quadruple  expansion  add  still  more  initial 
expense,  which  is  the  price  to  be  paid  for  increased 
steam  and  coal  economy.  Evidently  a  limit  will  be 
reached  somewhere,  beyond  which  successive  expan- 
sion cylinders  will  cost  more  than  the  fuel  saving  will 
warrant,  and  this  limit  is  found  with  the  two-stage  or 


112 


POWER 


compound  engine  in  stationary,   and  the  three-stage 
or  triple  engine  in  marine  practice. 

When  the  two  cylinders  of  a  compound  or  two-stage 
expansion  engine  are  in  line  with  each  other  and  both 

pistons  are  on  the  same 
piston  rod,  the  engine 
is  called  a  tandem  com- 
pound. Fig.  89  shows 
a  cross-section  of  a 
tandem  compound  ar- 
rangement with  two 
FIG.  89  slide-valves,  and  Fig. 

90  a  similar  arrange- 
ment with  a  piston-valve  on  the  high-pressure  cylinder 
and  a  slide-valve  on  the  low-pressure.  The  exhaust 
from  the  high  pressure  is  led  to  the  steam  chest  of  the 
low.  The  external  appearance  of  a  tandem  compound 
engine  with 
slide-valve  is 
shown  in  Fig. 

91,  and  another 
tandem     com- 
pound of  larger 
size  with  Cor- 
liss valve  is 
shown  in  Fig. 

92.  It  is  per- 
haps more  com- 
mon to  arrange  the  cylinders  of  compound  engines  side 
by    side,   with    separate    rods    and    cranks,    and    this 
arrangement  is  called  a  cross-compound.     A  vertical 
cross-compound  engine,  having  a  piston-valve  on  its 


FIG.  90 


EFFICIENCY  IN   STEAM-POWER 


113 


FIG.  91 


FIG.  92 


114 


POWER 


high-pressure  cylinder 
and  on  the  low-pressure 
a  slide  valve,  is  shown 
in  Fig.  93.  Another 
larger  horizontal  one 
with  slide  valves  is 
shown  in  Fig.  94,  and  a 
still  larger  cross-com- 
pound slide-valve  en- 
gine with  gridiron  valve 
is  shown  in  Fig.  95. 
Two  larger  Corliss  com- 
pounds, one  vertical 
and  the  other  horizon- 
FlG  93  tal,  are  shown  in  Figs. 

96,    97.     One    cylinder 

placed  vertical  and  the  other  horizontal  gives  what 
is  called  the  angle-compound  construction,  such  as  is 
used  in  many  larger  railway  and  central  station  power 
houses  in  pairs,  as  shown  in  Fig.  98. 


FIG.  94 


EFFICIENCY  IN  STEAM-POWER 


115 


FIG.  95 


No  piston  en- 
gines are  made 
with  cylinders 
enough  in  num- 
ber and  size  to 
be  capable  of 
utilizing  the  full 
expansion  of  the 
steam,  because 
the  increased 
cost  of  the 
larger  cylinders 
more  than  overbalances  the  saving  of  fuel.  It  has 
remained  for  the  steam-turbine  to  supply  a  cheaper 
means  of  taking  full  advantage  of  high  initial  and 
low  final  pressures  than  indefinite  multiplication  of 

large  cylinders. 
The  steam- 
turbine  prob- 
lem, however, 
is  not  so  simple 
as  it  seems, 
for,  as  already 
pointed  out,  it 
is  necessary 
but  difficult  to 
arrange  wheels 
and  vanes  cap- 
able of  moving 
fast  enough  to 
make  the  best 
FIG.  96  use  of  the  high 


116 


POWER 


velocity  steam  jet.     It  is  easy,  however,  to  get  complete 
steam  expansion  in  the  nozzle  forming  the  jet  and  to 


FIG.  97 


form  jets  having  such  a  velocity  as  will  represent  all  the 
work  the  steam  is  capable  of  doing.     To  get  a  clear  idea 


FIG.  98 


EFFICIENCY  IN  STEAM-POWER  117 

of  the  difficulty  to  be  met  it  is  necessary  to  know  the 
velocities  of  steam  jets,  which  the  thermodynamic  laws 
supply  means  to  calculate.  For  example,  steam  expand- 
ing from  150  pounds  per  square  inch  boiler  pressure  to 
atmosphere  would  acquire  a  velocity  of  3000  feet  per 
second  or  2000  miles  per  hour,  about  forty  times  as 
fast  as  the  average  express  train;  and  if  it  expanded 
to  a  vacuum  96  per  cent  perfect,  its  velocity  would  be 
4100  feet  per  second  or  nearly  3000  miles  per  hour. 
Perfectly  executed  expansion  of  the  first  sort  would  give 
to  the  jet  energy  of  motion  equal  to  15  per  cent  of  the 
heat  put  into  the  steam,  and  perfectly  executed  expan- 
sion from  boiler  pressure  to  the  vacuum  would  make  jets 
having  energy  of  motion  equal  to  about  28  per  cent  of 
the  heat  content  of  the  live  steam.  No  higher  efficien- 
cies than  these  would  be  possible,  no  matter  how  perfect 
the  mechanism.  Just  in  proportion  as  the  velocities  of 
wheels  and  these  fast  steam  jets  are  correctly  adjusted, 
and  leakage  and  friction  losses  reduced,  so  may  these 
efficiencies  be  produced,  otherwise  not.  Single  vane 
wheels  should  run  at  speeds  a  little  more  or  less  than 
half  the  jet  velocity,  so  that  for  the  complete  expansion 
to  a  vacuum  the  speed  of  the  wheel  should  be  such  as 
to  give  about  2000  feet  per  second  vane  velocity,  at 
which  value  the  wheel  would  burst.  To  prevent 
blowing  up  the  wheels,  governors  are  used  to  keep  the 
speed  down  to  a  safe  value,  at  which  speed  only  a  part 
of  the  energy  of  the  steam  jet  can  be  taken  up  by  the 
wheel,  so  that  all  such  single-wheel  turbines  are  neces- 
sarily wasteful.  Small  turbines  are,  however,  made, 
and  being  cheap  find  some  useful  fields.  One  of  these 
machines  carries  little  cups  on  the  circumference  of 


118 


POWER 


FIG.  99 


the  wheel  and  a  number  of  nozzles  are  spaced  around, 
as  shown  in  Fig.  99;  while  another  has  curved  slits 
cut  in  its  edge  to  form  the  vanes, 
as  shown  in  Fig.  100.  In  the  latter 
case  the  steam  passes  through  the 
wheel  and  this  is  the  more  com- 
mon form.  Another  way  of  mak- 
ing vanes  on  the  edge  of  wheels 
for  the  steam  to  pass  through 
from  .side  to  side  is  shown  in  Fig. 
101,  in  which  .they  are  dovetailed 

into  a  groove.  The  external  appearance  of  a  single- 
wheel  turbine,  constructed  as  shown  in  Fig.  100,  is 
illustrated  in  Fig.  102,  as  built  to 
drive  two  electric  generators  by 
two  gear-wheels,  which  reduce  the 
speed  to  a  safe  value  for  the  electric 
generator.  The  two  large  central 
boxes  contain  these  gears,  while 
the  narrow  chamber  at  the  right 
end  is  the  wheel  chamber,  the  nozzle  valves  appearing 
plainly  on  the  circumference.  The  problem  of  correct 
adjustment  of  wheel  speed  to  steam 
jet  speed  necessary  for  high  economy, 
yet  allowing  the  wheels  to  rotate  slow 
enough  to  avoid  bursting,  or  slow 
enough  to  be  adapted  to  drive  stand- 
ard machinery,  most  of  which  does 
not  rotate  very  fast,  has  been  solved 
only  within  the  last  ten  years.  The 
method  applied  to  this  solution  is  similar  to,  but  more 
perfectly  carried  out  than,  that  used  in  the  piston 


FIG.  100 


FIG.  101 


EFFICIENCY  IN   STEAM-POWER 


119 


FIG.  102 


engines,  that  of  division  of  the  duty  into  stages. 
Economical  low-speed  steam  turbines  must  be  multi- 
stage machines,  and  the  staging  may  be  carried  out 
in  two  characteristic  ways.  In  the  first  way,  called 
pressure  stag- 
ing, the  full 
velocity  due  to 
the  final  and 
initial  pressures 
is  never  real- 
ized, but  only 
a  part,  then  a 
little  more,  and 
so  on.  Thus, 
if  a  series  of 

chambers  be  arranged  in  a  row,  as  in  Fig.  103,  with  a 
steam  supply  pipe  leading  to  the  first,  and  nozzles  leading 
from  chamber  to  chamber  of  appropriate  size  to  reduce 
the  pressure  in  the  successive  chambers  by  say  50  pounds 
per  nozzle,  the  last  chamber  being  connected  to  a  con- 
denser,  Siiid  in  addition  a  vane 
wheel  be  placed  in  each  chamber, 
then,  instead  of  one  jet  with  a 
velocity  equal  to  the  whole  drop 
in  pressure,  there  are  five  jets  in 
series,  each  with  a  velocity  due  to 
50  pounds  pressure,  a  very  much 
smaller  amount.  When  many  nozzles  are  placed  be- 
tween stages,  the  partition  begins  to  resemble  the 
vanes ;  differences,  however,  exist  in  shape  and  area 
of  opening.  A  view  of  a  casing  for  a  multistage  tur- 
bine in  which  the  nozzles  look  like  the  vanes  them- 


FIG.  103 


120 


POWER 


selves  is  shown  in  Fig.  104.  The  other  way  of  meeting 
the  velocity  difficulty,  and  the  second  method  of  solu- 
tion, is  to  use  the  principle  of  successive  impulse,  or  a 
series  of  bounces,  the  steam  being  given  its  full  velocity 
in  one  nozzle,  all  the  wheels  rotating  in  a  chamber  of 
the  same  low  pressure,  maintained  by  the  condenser, 


FIG.  104 

and  the  steam  jet  striking  one  wheel  after  another,  being 
guided  between  by  openings  in  fixed  partitions.  Each 
time  the  steam  strikes  a  vane  it  gives  it  a  push  and 
loses  some  velocity,  so  that  finally  it  emerges  with  no 
velocity,  having  given  up  its  energy  to  the  wheels  in 
many  velocity  stages,  the  process  being  termed  velocity 
staging.  Modern  turbines  are  built  for  both  methods 
of  staging,  using  the  jet  both  by  impulse  and  reaction, 


EFFICIENCY  IN   STEAM-POWER 


121 


and  with  all  sorts  of  structural  details,  but  in  every 
machine  there  are  great  numbers  of  fixed  guides  and 
moving  vanes  differing  more  in  curvature  and  areas  of 
passages  than  in  general  external  form.  In  Fig.  105 
is  shown  a  cross-section  of  a  four-stage  turbine  through 
the  nozzle  and  guides.  The  complete  machine,  de- 


FIG.  105 


FIG.  106 


signed  for  about  15,000  h.  p.,  is  illustrated  partly  in 
section  in  Fig.  106,  which  shows  the  electric  generator 
above  mentioned,  rotating  on  the  same  vertical  shaft 
as  the  wheels.  The  interior  of  the  power  station  of  the 
Commonwealth  Electric  Co.,  containing  machines  of 
this  type,  is  shown  in  Fig.  107.  This  station  is  designed 
for  about  150,000  h.  p.  One  of  the  most  interesting 


122 


POWER 


FIG.  10, 


installations  recently  made  is  that  for  the  new  battle- 
ship, North  Dakota,  built  by  the  Fore  River  Co.,  and 
which  is  equipped  with  about  30,000  h.  p.,  shown  in 
Fig.  108,  and  which  on  trial  made  a  record  for  economy. 


FIG.  108 


EFFICIENCY  IN   STEAM-POWER 


123 


This  turbine  complete,  as  it  appeared  in  the  shop,  is 
shown  in  Fig.  109,  and  the  upper  half  of  the  casing, 


FIG.  109 

in  which  the  guide  vanes  are  clearly  seen,  in  Fig.  110, 
while  the  wheels  with  successive  rows  of  vanes  fitting 
between    the    rows    of 
guides    are    shown    in 
Fig.  111. 

These  steam-turbines 
can  be  built  at  about 
one-half  the  cost  of  com- 
pound piston  engines 
or  less,  so  that  they 
offer  a  cheaper  means 
of  developing  into  use-  FIG.  no 


124 


POWER 


ful   work  the  work  capabilities  of   expanding   steam. 

This  fact  has  led  to  their  adoption  in  place  of  additional 

cylinders  to  compound 
engines,  the  exhaust 
from  the  compound 
running  the  turbine 
instead  of  passing  to 
a  third  or  fourth  cyl- 
inder of  triple  and 
quadruple  engines. 
One  such  installation, 
just  completed  in  the 


New  York  Subway 
power  house  (Fig.  112),  was  able  to  develop  as  much 
power  in  the  turbine  as  did  the  large  compound  engine, 
the  waste  steam  from  which  supplied  the  turbine,  and 


FIG.  112 


EFFICIENCY  IN  STEAM-POWER 


125 


so  brought  down  the  coal  consumption  to  a  trifle  over 
one  pound  per  hour  for  each  horse-power,  the  most 
economical  record  for  a  steam-power  station  in  daily 
service. 

The  reduction  of  the  pressure  in  the  exhaust  passage 
of  the  engine,  such  as  happens  when  condensers  are 
used,  and  which  may  be  made  lower  and  lower  as  the 
condensing  equipment  is  better  and  better,  increases 
primarily  the  work  that  the  expanding  steam  may  do, 
and  that  may  be 
realized  if  the  en- 
gine is  of  suitable 
type  or  construc- 
tion. Condensing 
equipment  may, 
therefore,  be  con- 
sidered as  appara- 
tus designed  pri- 
marily for  economy 
in  the  use  of  steam 
by  engines,  and 
there  have  been 
great  advances  in 

recent  years  in  the  attainment  and  maintenance  of  a 
good  vacuum  for  just  this  purpose;  but  space  will  not 
permit  of  a  consideration  of  condensing  equipment, 
however  desirable  that  might  be,  beyond  a  few  pictures 
to  illustrate  the  nature  of  modern  condensers.  Passing 
the  exhaust  steam  through  a  cast-iron  casing  filled  with 
small  tubes  through  which  water  is  pumped,  is  the 
surface  condensing  method.  One  very  large  surface 
condenser,  such  as  might  be  used  with  steam  turbines, 


FIG.  113 


126 


POWER 


FIG.  114 


is  shown  in  Fig.  113,  with  one  end  plate  removed  to 

show  the  tubes  starting  from  the  inner  partition  plate. 

Another  condenser  of  smaller  size  is  shown  in  Fig. 

114.  Surface    condensers    of   this   class   require   two 

pumps  at  least  to  oper- 
ate them,  one  to  send 
the  circulating  water 
through  the  tubes, 
which  water  is  often 
taken  from  a  near-by 
river  and  need  not  be 
especially  clear  or  pure, 

a  fact  that  prompts  the  location  of  plants  on  water 

fronts,  and  the  other  to  pump  out  from  the  vacuum 

chamber  all  the  water  of  condensation.     This   latter 

type  of  pump  is  called  an  air-pump,  vacuum-pump, 

or     hot-well 

pump.        One 

common  type  of 

vacuum  -  pump 

used    for    this 

purpose     is 

shown   in    Fig. 

115.  ft  has  a 
conical     piston 
which  is  moved 
up  and  down  in 
its  cylinder  by  a 
vertical  steam- 
engine  above.     The  cylinder  has  slits  in  the  side,  and 
the   casing   surrounding  the  cylinder   into  which   the 
water  from  the  cylinder  runs  has  a  curved  guide.     The 


FIG.  115 


EFFICIENCY  IN   STEAM-POWER 


127 


piston  in  its  descent  strikes  the  water  in  the  bottom. 
By  reason  of  the  conical  head  and  the  curved  guide 
this  water  is  projected  through  the  slits  into  the  cylinder 
above  the  piston,  which  immediately  after  rises,  closing 
the  slits  and  pushing  out  the  water  through  the  valves 
shown.  Sometimes  a  simple  direct-acting  steam-pump 
is  used,  placed  below  the  condenser,  so  that  the  water 
of  condensation 
can  run  into  its 
cylinder  easily; 
and  one  of  these 
surface  con- 
densers so 
equipped  is 
shown  in  Fig. 
116,  on  which 
there  also  ap- 
pears at  the 
right-hand  side 
a  centrifugal 
pump  for  cir- 
culating water. 
These  centrifugal  pumps  are  much  like  fans  which  are 
fairly  common  and  easily  understood.  A  wheel  runs 
in  the  casing,  and  this  wheel  has  vanes  or  radial  or 
curved  arms  on  it,  and  by  the  mere  act  of  rotation 
the  water  which  enters  at  the  center  is  thrown  off 
to  the  circumference,  escaping  tangentially  through 
the  pipe.  Centrifugal  pumps  are  commonly  used  for 
this  purpose  because  they  contain  no  valves,  and 
permit  the  use  of  water  that  may  contain  floating 
matter,  such  as  always  occurs  when  it  is  taken  directly 


FIG.  116 


128 


POWER 


FIG.  117 


from  rivers. 
Another  con- 
denser of  similar 
form,  having 
the  two  pumps 
connected  to  a 
single  steam- 
cylinder  and  lo- 
cated on  oppo- 
site sides  of  it, 
is  shown  in  Fig. 
117.  A  surface 
condenser  with  an  extension  at  the  bottom  for  catching 
water,  and  provided  with  an  independent  pump  for 
removing  the  water  alone,  is  shown  in  Fig.  118,  while 
another  surface  condenser  of  the  vertical  form  is  shown 
in  Fig.  119.  This  one  has  a  centrifugal  pump  to  re- 
move the  water 
of  condensa- 
tion, but  driven 
by  a  directly 
connected  elec- 
tric motor. 
Some  surface 
condensing 
equipment  set 
beside  steam- 
turbines  for 
handling  their 
exhaust  is 
shown  in  Fig. 
120,  illustrating 


FIG.  118 


EFFICIENCY  IN  STEAM-POWER 


129 


their  relation,  and  showing,  especially  in  the  upper 
picture,  the  addition  of  another  or  third  pump  in  the 
operation  of  these  condensers.  This  is  called  a  dry 
vacuum-pump,  and  its  business  is  to  pump  out  of  the 
vacuum  chamber  all  substances  collecting  there  that 
are  incapable  of  condensing  by  contact  with  the  cold 
water  tube.  All  water  contains  uncondensable  gases 
dissolved  in  it,  such  as  air,  carbonic  acid,  or  the  gases 
generated  by  decaying 
animal  matter.  When  this 
water  enters  the  boiler,  the 
gases  are  driven  off  and 
pass  through  the  engine 
with  the  steam,  but  when 
the  steam  condenses,  these 
gases  do  not  enter  the  water 
again,  but,  on  the  contrary, 
collect  in  the  condenser 
vacuum  chamber,  tending 
to  destroy  the  vacuum  as 
they  collect.  When,  as  in 
the  case  of  turbines,  an 

extremely  high  vacuum  is  desirable,  then  an  additional 
pump  to  draw  off  these  gases  as  they  collect  is  added, 
and  this  dry  air-pump  sucks  the  gases  out,  compresses 
them  up  to  the  atmospheric  pressure,  and  discharges 
them  into  the  air.  In  the  upper  part  of  the  figure  at 
the  left  hand  is  clearly  shown  a  steam-driven,  dry 
vacuum-pump  for  removing  these  gases  from  the  hori- 
zontal condenser,  which  receives  the  exhaust  from  the 
steam-turbine.  Another  view  of  a  turbine  condensing 
equipment  of  the  same  general  character  is  shown  in 


FIG.  119 


130 


POWER 


Fig.  121,  representing  the  Port  Morris  power  station  of 
the  New  York  Central  Railroad,  supplying  current  for 
operating  electric  trains  from  the  Grand  Central  to 
Croton-on-the-Hudson.  The  vertical  turbines  dis- 
charge their  steam 
into  horizontal  sur- 
face  condensers, 
and  centrifugal 
pumps,  one  of  which 
is  shown  in  the  fore- 
ground, circulate 
water  from  the 
East  River  through 
the  condenser ;  a 
vacuum  or  hot-well 
pump,  not  shown, 
removes  the  con- 
densation, while  a 
dry  vacuum-pump 
for  each  condenser, 
shown  at  the  left, 
removes  the  non- 
condensable  gases. 
When  circulating 
water  is  not  avail- 
FIO.  120  able  in  large  quan- 

tities, as  is  the  case 

in  many  localities,  either  the  engines  must  be  operated 
non-condensing,  which  is  wasteful,  or  a  small  supply  of 
water  may  be  conserved  by  cooling  it  after  the  con- 
denser has  heated  it,  and  so  make  it  available  for  use 
over  and  over  again,  of  course  with  some  evaporation 


EFFICIENCY   IN   STEAM-POWER 


131 


losses.  When  water  is  scarce,  it  is  always  a  question 
whether  or  not  the  saving  in  coal  consumption  due  to 
condensing  operation  is  warranted  by  the  extra  cost  of 
water-cooling  equipment,  but  there  are  many  cases 
where  the  cooling  equipment  is  entirely  justified.  To 
illustrate  the  nature  of  this  apparatus  there  is  presented 


FIG.  121 


Fig.  122,  showing  a  cross-section  of  part  of  a  power 
house,  on  the  roof  of  which  is  placed  a  cooling  tower ; 
the  water  from  the  surface  condenser  below  is  pumped 
to  this  tower  and  trickles  down  through  it  over  the 
surface  of  wood  or  tile  or  metal,  as  the  case  may  be, 
while  a  fan,  shown  at  the  side  of  the  tower,  blows  air 
up  over  the  wet  surface  to  cool  the  water  to  a  tempera- 
ture even  lower  than  the  air  itself.  The  cooled  water 
runs  down  and  is  used  over  again  in  the  condenser. 


132 


POWER 


The  diagram  also  shows  a  vacuum  or  hot-well  pump, 
returning  the  condensed  steam  to  the  boiler,  and  the 
dry  vacuum-pump  for  removing  non-condensable  gases. 
This  principle  of  cooling  is  merely  the  passing  of  water 
in  thin  sheets  over  solid  surfaces  in  a  tower.  Another 
method  is  illustrated  in  Fig.  123,  which  represents 

the  spray  nozzle 
system.  The  water 
issues  through 
specially  designed 
nozzles,  forming  a 
fine  spray  which 
drops  into  tanks 
after  cooling  while 
suspended  in  the 
air.  With  many 
large  reciprocating 
engines,  more 
especially  those  of 
the  vertical  type, 
another  form  of 
condenser  is  often 
used,  in  which  the 
steam  and  water 
*mix  and  to  which  a  long  tail  pipe  is  added  to  avoid 
the  necessity  for  pumping  out  from  the  vacuum  space 
the  water  of  condensation  mixed  with  the  injection  water. 
This  pipe  is  long  enough  to  resist  the  barometric  pres- 
sure, and  so  is  somewhere  in  the  neighborhood  of  30 
feet  high,  and  at  the  bottom  dips  into  the  discharge 
water  canal.  Such  a  condenser  is  shown  in  Fig.  124. 
The  large  pipe  on  the  right  is  the  engine  exhaust-steam 


FIG.  122 


EFFICIENCY  IN   STEAM-POWER 


133 


pipe  leading  to  the  condenser,  with  a  branch  to  the 
roof  in  case  the  condenser  becomes  inoperative.  The 
pipe  at  the  left  nearest  the  condenser  supplies  the  cir- 
culating or  injection  water,  which  escapes  from  the 
tail  pipe  at  the  bottom  of  the  condenser.  The  pipe 
leading  from  the  condenser  at  the  top  and  descending 
farthest  to  the  left  is 
the  dry  air  pipe.  A 
cross-section  of  one  of 
these  condensers  is 
shown  in  Fig.  125. 
Water  enters  near  the 
top,  runs  through  ori- 
fices and  over  the  edges 
of  plates  in  cascades, 
dripping  through  the 
chamber  receiving  the 
steam,  condensing  it. 
The  waters  of  conden- 
sation and  injection 
together  run  down  the 
tail  pipe.  At  the  top  FlG  123 

of    the    chamber    the 

non-condensable  gases  collect  and  are  pumped  out  by 
the  dry  vacuum-pump.  An  external  view  of  another 
form  of  the  barometric  type  of  condenser  is  shown  out- 
side the  power  house  in  Fig.  126.  This  is  a  very  large 
one,  the  size  of  which  can  be  judged  by  comparing  it 
with  the  man  standing  on  the  ladder  at  the  side.  A 
large  vertical  engine  equipment,  with  barometer  con- 
denser, is  shown  in  Fig.  127,  which  is  a  diagram  of  a 
cross-section  of  that  part  of  the  house  near  the  engine, 


134 


POWER 


showing  the  basement  and  engine  floors.  In  the  base- 
ment, it  will  be  noted,  there  is  a  small  steam-engine 
driving  a  centrifugal  pump  which  supplies  water  to  two 

barometric  condensers, 
which  can  be  recog- 
nized by  their  bulblike 
form.  From  these  the 
water  runs  down 
through  a  long  curved 
tail  pipe. 

Careful   tests   of 
engines  have  indicated 


I 


FIG.  124 


FIG.  125 


that  a  good  deal  of  the  steam  that  enters  them  does  not 
do  any  work  at  all;  and  this  part  that  does  not  work  is 
itself  divisible  into  two  parts :  first,  the  part  which  con- 


EFFICIENCY  IN  STEAM-POWER 


135 


denses  in  the  cylinder  as  it  enters ;  and  second,  the  part 
which  leaks  past  piston  or  valves  into  the  exhaust 
before  it  has  a  chance  to  work.  Improved  machine 
work  and  more  perfectly  designed  valves  and  pistons 
have  reduced  the  leak- 
age losses  a  good  deal, 
but  it  seems  to  be  im- 
possible ever  to  elimi- 
nate all.  The  reduction 
of  the  condensation 
loss  has  been  a  subject 


FIG.  126 


FIG.  127 


of  study  for  a  good  many  years.  It  is  greatest  when 
the  cylinder  is  most  cold,  at  the  time  when  the  steam 
enters,  and  this  is  the  case  when  the  expansion  in  that 
cylinder  has  been  greatest,  because  by  expansion  the 


136 


POWER 


temperature  of  the  steam  falls,  making  the  walls  colder 
than  they  were,  and  promoting  condensation  at  the 
next  admission  of  steam.  All  sorts  of  devices  have 
been  tried,  including  steam-jackets,  but  about  all  that 
have  survived  are  the  use  of  superheat  and  multiple  ex- 
pansion. A  multiple  expansion  engine  keeps  the  range 
of  temperature  in  any  one  cylinder  less  than  it  would 
be  in  a  single  cylinder  carrying  out  the  same  total  ex- 
pansion. This 
type  of  engine, 
therefore,  suf- 
fers less  from 
cylinder  con- 
densation loss. 
It  has  also  been 
found  that 
steam  heated 
more  after  it  is 
made,  or  super- 
heated, as  it  is 
called,  may  im- 
prove condi- 
tions to  the  extent  of  10  per  cent  or  thereabouts,  and 
superheating  is  being  more  and  more  practised  for  this 
reason.  In  Fig.  128  is  shown  a  cross-section  of  one  of 
the  horizontal  water-tube  class  of  boilers  to  which 
a  superheater  has  been  added.  This  is  nothing  more 
than  a  double  row  of  U  -tubes  placed  in  the  path  of  the 
hot  gases  at  the  top  of  the  first  pass.  Steam  passes 
from  the  regular  drum  through  these  tubes  and  gets 
further  heated  or  superheated  before  it  enters  the 
steam-pipe  on  its  way  to  the  engine. 


FIG.  128 


EFFICIENCY  IN   STEAM-POWER 


137 


ANALYSIS  OF  THE  AVERAGE  LOSSES  IN  THE  CONVERSION  OF  ONE 
POUND  OF  COAL  INTO  ELECTRICITY 


% 

% 

1.  B.  T.  U.  per  pound  coal  supplied      .     .     . 
2.  Loss  in  ashes     
3.  Loss  to  stack                                  .... 

100.0 

2.4 
227 

4.  Loss  in  boiler  radiation  and  leakage      .     . 
5.  Returned  by  feed-water  heater     .... 
6.  Returned  by  economizer                .... 

3.1 

6.8 

8.0 

7.  Loss  in  pipe  radiation                     .... 

02 

8    Delivered  to  circulator 

1  6 

9    Delivered  to  feed  pump 

1  4 

10.  Loss  in  leakage  and  high-pressure  drips 
11,  Delivered  to  small  auxiliaries 

1.1 
04 

12    Heating  building 

02 

13.  Loss  in  engine  friction 

08 

14.  Electrical  losses 

03 

15.  Engine  radiation  losses   
16.  Rejected  to  condenser 

0.2 
60  1 

17.  To  house  auxiliaries 

02 

Heat  supplied  and  waste  returned     .     . 
Heat  lost  in  various  ways    

109.9 
99.6 

99.6 

10.3% 

j    of  heat 
supplied 

After  all  these  improvements  of  engine,  boiler,  and 
auxiliary  equipment,  and  many  others  of  minor  im- 
portance, each  of  which  is  the  result  of  a  great  amount 
of  patient  study,  there  is  yet  required  on  the  part  of 
the  engineer  good  judgment  to  decide  whether  the 
expense  incurred  in  saving  heat  will  be  warranted  by 
the  saving  of  money,  as  true  economy  is  measured  by 
lowest  net  cost  of  power.  This  judgment  must  in 


138  POWER 

every  case  be  based,  however,  on  the  heat  waste  that 
is  to  be  reduced;  and  while  the  various  wastes  are 
differently  distributed  in  every  plant,  yet  a  fair  average 
of  the  best  is  of  value. 

A  comparatively  recent  analysis  of  the  distribution 
of  the  energy  supplied  in  a  pound  of  coal  in  a  large 
central  power  station,  about  as  highly  efficient  as  any, 
is  that  made  by  H.  G.  Stott,  superintendent  of  motive 
power  of  the  Interborough  Railroad,  quoted  above, 
and  which  will  show  just  where  the  heat  goes  after  the 
exercise  of  best  skill  and  judgment  in  the  selecting  and 
managing  of  the  apparatus. 

From  this  it  appears  that  60  per  cent  of  the  heat  of 
the  coal  is  finally  discharged  in  the  condensing  water 
and  nearly  23  per  cent  to  the  stack  for  the  maintenance 
of  draft,  these  two  together  aggregating  about  83  per 
cent  of  the  heat  in  the  coal.  No  way  has  ever  been 
found  to  reduce  this  heat  that  must  be  delivered  to 
the  condensing  water.  It  is  an  essential  characteristic 
of  the  steam  system;  and  the  fact  that  steam  in  con- 
densing, at  however  low  a  pressure,  does  give  up  to 
the  condensing  water  so  large  an  amount  of  heat,  con- 
stitutes a  final  limit  of  efficiency  inherent  to  this  sys- 
tem. If  the  system  were  non-condensing,  a  larger 
per  cent  would  have  been  discharged  into  the  air  than 
is  received  by  the  condensation  water.  With  regard 
to  the  stack  loss,  this  can  be  entirely  eliminated,  but 
this  elimination  would  mean  the  substitution  of  some 
other  means  of  producing  draft  and  no  means  has  as 
yet  been  found  that  is  as  cheap  as  the  loss  itself.  In 
other  words,  the  operation  of  fans  or  any  other  devices 
for  maintaining  draft  has  been  found  to  cost  more 


EFFICIENCY  IN  STEAM-POWER  139 

in  the  long  run  than  to  build  a  chimney  and  allow  this 
23  per  cent  of  the  coal  heat  to  escape  up  it  to  produce 
the  draft  needed  to  burn  the  coal  at  a  suitable  rapid 
rate. 

It  is  not  so  much  the  object  of  engineers  to  reach 
high  economy  in  the  use  of  coal ;  it  is  not  so  essential 
that  the  greatest  amount  of  coal  energy  be  turned  into 
work  or  that  in  the  use  of  coal  for  power  the  heat  wastes 
be  reduced  to  a  minimum.  The  question  is  really 
far  broader  than  this.  The  problem  to  be  met  is  strictly 
and  properly  that  of  minimum  waste,  but  minimum 
waste  of  everything,  not  only  coal  or  water,  but  labor 
and  investment.  It  would  not  pay  to  build  a  power 
plant  costing  four  times  as  much  as  existing  plants, 
even  if  the  coal  consumption  could  be  reduced  to  a 
half  of  what  it  is,  and  this  fact  can  only  be  appreciated 
by  some  figures.  According  to  the  last  census  report 
the  average  output  of  the  central  power  stations  of 
the  United  States  was  about  25  per  cent,  or  one-fourth 
of  their  capacity.  Suppose  that  these  stations  cost, 
as  the  better  ones  do,  $120  per  horse-power  to  build, 
and  that  there  be  set  aside  each  year  a  certain  sum 
for  depreciation,  from  which  worn-out  apparatus  is 
to  be  renewed  and  the  plant  perpetuated,  and  another 
sum  yearly  representing  the  interest  on  the  investment ; 
another  sum  for  the  salaries  of  officers  and  superin- 
tendents ;  still  another  for  insurance  and  taxes  and 
for  similar  items,  altogether  amounting  perhaps  to 
12  per  cent  per  year  on  the  first  cost.  Then  if  this 
plant  worked  all  day  and  every  day  at  full  load 
there  would  be  charged  against  the  cost  of  power  a 
fixed  sum  of  $14.40  per  year  per  horse-power.  If  the 


140  POWER 

plant,  on  the  contrary,  worked  on  the  average  to  only 
one-fourth  of  its  capacity,  then  this  fixed  charge  per 
horse-power  would  be  four  times  as  much  as  before,  or 
$57.60.  It  may  be  assumed  that  in  stations  of  the 
kind  under  consideration  this  fixed  investment  charge 
is  fully  as  large  as  the  cost  of  coal  and  labor  and  other 
supplies  put  together,  from  which  it  appears  that  a 
saving  of  10  per  cent  or  15  per  cent  in  coal  will  affect 
the  cost  of  power  not  as  much  as  5  per  cent,  even  if 
no  additional  apparatus  were  required;  but  if  the  fixed 
and  operating  charges  on  needed  additional  apparatus 
were  to  be  included,  there  might  actually  be  a  loss 
incurred  and  power  cost  more  than  without  the  addi- 
tional equipment  when  wasting  some  coal.  This 
would  more  surely  be  the  case  if  much  more  additional 
labor  were  required  to  take  care  of  the  additional 
apparatus.  In  a  comparatively  recent  discussion  of 
this  point,  Mr.  F.  G.  Clark,  superintendent  of  the 
Pennsylvania  and  Long  Island  R.  R.  power  station 
in  Long  Island  City,  gave  the  following  figures  for 
various  average  outputs  of  power  stations  from  100 
per  cent  down  to  20  per  cent  of  their  capacity,  the  figures 
applying  to  a  steam-turbine  station  in  which  the  fixed 
charges  are  less  than  for  a  piston-engine  station,  be- 
cause the  turbines  are  themselves  considerably  cheaper 
than  piston  engines.  The  power  is  here  measured  in 
kilowatts,  an  electrical  unit  equivalent  to  one  and 
one-third  horse-power. 


EFFICIENCY  IN  STEAM-POWER  141 

POWER  COST  DISTRIBUTION  WITH  AVERAGE  STATION  OUTPUT 


Average  output  of  station 

100% 

80% 

60% 

40% 

20% 

Total  cost  per  K.W.  year 

$35 

$40 

$49 

$65 

$100 

Investment  charges    .     . 

26% 

29% 

31% 

36% 

46% 

Coal  charges      .... 

53% 

54% 

53% 

49% 

39% 

Labor  

12% 

9% 

9% 

9% 

9% 

Miscellaneous    .... 

9% 

8% 

7% 

6% 

6% 

100 

100 

100 

100 

100 

It  will  appear  quite  evident,  from  what  has  been 
said  above,  that  not  only  has  the  scientific  study  of 
the  reduction  of  heat  waste  in  steam-power  systems 
been  put  upon  a  firm  and  substantial  basis  through  the 
assistance  of  thermodynamics,  and  that  engineers  are 
engaged  in  patiently  calculating,  predicting,  testing, 
and  recalculating  possible  improvements,  but  that  their 
attention  is  also  directed  toward  the  broader  questions 
of  net  economy.  Its  attainment  is  a  combination  of 
strictly  technical  with  business  problems,  and  involves 
the  use  of  methods  that  permit  of  intelligent  judgment 
of  what  should  be  done  before  it  is  done,  and  of  the  true 
economical  value  of  new  proposals  for  doing  old  things. 

Such  inventors  as  those  whose  work  caused  the  in- 
dustrial revolution  have  no  equally  important  place  in 
the  modern  social  organization.  Their  knowledge  was 
confined  to  the  wheels,  rods,  and  cylinders  referred  to 
by  the  historian,  whereas  to-day,  while  we  are  still 
somewhat  dependent  on  such  men,  real  progress  can 
be  attained  only  by  a  far  higher  order  of  direction, 
requiring  trained  engineers  who  must  be  at  once  prac- 
tical mechanics,  scientists,  economists,  financiers,  and 
managers  of  men. 


PROCESSES   AND   MECHANISM    OF   THE    GAS-POWER 
SYSTEM 

IT  was  not  until  the  establishment  of  the  relations 
of  heat  to  work,  and  the  conditions  for  transforming 
the  former  into  the  latter,  as  embodied  in  that  body 
of  the  principles  of  physical  laws  known  as  thermo- 
dynamics, that  the  great  possibilities  of  the  gas-power 
system  were  recognized.  In  the  steam  system  of  secur- 
ing work  from  heat,  the  heat  is  added  to  water,  turning 
it  into  high-pressure  steam;  the  steam  then  acting 
like  a  compressed  spring  can  either  give  itself  a  velocity 
as  in  the  turbine,  or  push  on  a  piston  as  in  the  piston 
engine.  No  matter  which  way  it  acts  in  doing  work, 
much  of  the  heat  put  into  the  steam  in  making  it  is 
carried  away  by  the  exhaust  steam,  estimated  at  about 
60  per  cent  even  when  working  with  a  good  vacuum, 
and  considerably  more  when  the  exhaust  steam  is 
discharged  into  the  atmosphere  without  condensing. 
No  matter  how  perfect  the  steam-engine  mechanism, 
these  conditions,  together  with  others  noted,  impose 
a  low  limit  on  the  efficiency  or  a  high  limit  on  the  waste 
heat.  As  a  matter  of  fact,  no  matter  what  the  system 
of  changing  heat  into  work,  there  will  be  limits  to  the 
possible  performance  of  even  a  perfect  mechanism, 
but  the  limit  is  different  for  different  systems.  The 
gas  system  has  a  much  higher  possible  efficiency  limit 

142 


MECHANISM  OF  GAS-POWER  143 

than  the  steam  system,  and  one  of  the  greatest  con- 
tributions of  thermodynamics  is  the  determination  of 
this  fact,  and  the  establishment  of  a  method  of  cal- 
culating the  limit  of  efficiency,  or  the  maximum  pos- 
sible amount  of  heat  that  may  be  transformed  into 
work  by  adding  the  heat  of  the  fuel  to  gases  instead  of 
to  steam,  using  the  springlike  action  of  gases  to  do 
work  on  pistons,  much  the  same  as  does  steam  in  piston 
engines. 

A  mass  of  any  gas,  such  as  air,  or  the  gaseous  prod- 
ucts of  combustion,  will,  if  confined  in  a  chamber  and 
there  heated,  suffer  a  rise  in  pressure;  and  this  gas  of 
increased  pressure  may  be  used  to  push  a  piston,  ex- 
panding as  the  piston  moves  and  continuing  the  push 
as  long  as  the  pressure  lasts.  Similarly,  if  the  heating 
be  continued  as  the  piston  advances,  the  pressure  may 
be  maintained  higher  or  longer  and  the  push  augmented. 
Early  attempts,  and  even  such  comparatively  recent 
ones  as  were  made  by  Captain  John  Ericsson  during 
our  Civil  War  period,  to  embody  such  gas  heating  and 
expanding  processes  in  mechanisms  to  constitute  a 
gas  or  hot-air  engine,  based  on  the  heating  of  air  in- 
closed in  and  between  cylinders  by  a  fire  outside, 
amounted  to  very  little  because  only  a  small  portion 
of  the  heat  of  the  fire  actually  reached  the  inclosed 
air,  and  of  this  small  amount  only  a  fraction  was  con- 
verted into  work.  A  still  more  serious  difficulty,  how- 
ever, was  encountered  in  the  rate  of  working,  as  air 
can  be  heated  only  very  slowly  through  plates,  so  that 
the  engine  had  to  be  enormously  big  to  give  a  little 
power  and  prohibitively  expensive  as  a  consequence. 
After  many  trials,  most  of  them  unsuccessful,  two  basal 


144  POWER 

principles  were  finally  recognized:  first,  that  some 
faster  method  of  heating  was  necessary;  and  second, 
that  air  or  other  gas  previously  compressed  by  a  piston 
before  heating  is  capable  of  yielding  more  work  for 
the  heat  it  receives  than  without  compression.  Heat 
must,  therefore,  be  added  directly  to  the  gas  without 
passing  through  plates;  and  by  compressing  the  gas 
higher  and  higher  before  heating,  the  efficiency,  or  work 
per  unit  of  heat,  may  be  extremely  high,  approaching 
even  80  per  cent,  and  this  may  be  realized  if  no  mechan- 
ical difficulties  are  encountered  in  carrying  out  the 
process.  Unfortunately  there  are  such  difficulties,  but 
35  or  40  per  cent  has  actually  been  realized  by  one  of 
these  gas  engines. 

Means  for  securing  the  rapid  heating  needed  are  found 
in  the  process  of  combustion  itself,  for  there  is  no  more 
rapid  method  of  making  cold  gases  hot  than  by  choos- 
ing such  gases  as  will  combine  chemically  or  burn, 
heating  themselves  as  the  combustion  proceeds. 
Early  attempts  were  made  to  use  coal  fires ;  air  pumped 
through  a  fire  inclosed  in  strong,  tight  chambers  be- 
came very  hot  almost  instantaneously,  and  the  problem 
seemed  to  be  solved.  However,  the  difficulty  of  regu- 
lating the  fire,  feeding  coal,  and  removing  ash  when 
the  furnace  was  bolted  inside  of  thick  metal  vessels, 
and  the  cutting  action  of  the  ash  dust  on  the  cylinder 
walls,  soon  showed  that  the  mechanical  difficulties  of 
this  process  were  too  serious.  Attention  was  then 
turned  to  an  older  combustion  process,  which,  for  some 
unexplainable  reason,  except  perhaps  an  unfounded 
fear  of  destruction,  had  not  received  much  attention, 
the  process  of  explosive  combustion  or  just  explosion. 


MECHANISM   OF  GAS-POWER  145 

All  fuel,  whether  solid  coal,  liquid  oil,  or  gas,  consists 
of  only  a  few  primary  combustible  substances  or  chem- 
ical elements,  which  when  combined  in  various  ways 
give  to  natural  fuels  their  special  form.  The  two 
important  combustible  elements  are :  first,  solid  black 
carbon,  familiar  in  a  variety  of  forms  itself,  as  lamp- 
black, charcoal,  or  diamond ;  and  second,  gaseous  hy- 
drogen, the  lightest  gas  known  and  so  used  for  inflating 
balloons,  making  them  able  to  float  in  air.  All  sorts 
of  carbon  and  hydrogen  compounds  are  known,  several 
hundred  in  number,  some  existing  as  gases,  some  as 
liquids,  and  others  as  solids,  but  all  useful  as  fuel,  - 
fuel  in  the  sense  that  when  heated  in  the  presence  of 
gaseous  oxygen  they  will  combine  chemically,  giving 
out  heat  very  rapidly  and  turning  into  two  other  gases : 
first,  carbonic  acid  gas,  the  gas  used  in  charging  soda 
water  ;  and  second,  water  vapor.  In  the  formation  of 
carbon  dioxide  one  particle  of  solid  carbon  unites  with 
two  particles  of  gaseous  oxygen,  making  one  particle 
of  gaseous  carbon  dioxide ;  and  in  the  formation  of  water 
vapor  two  particles  of  gaseous  hydrogen  combining 
with  one  particle  of  gaseous  oxygen  make  one  particle 
of  very  hot  water  vapor,  or  superheated  steam,  which, 
when  cooled,  may  become  liquid  water.  If  hydrogen 
be  mixed  with  oxygen  before  igniting  in  just  the  right 
proportion,  so  that  after  combustion  no  hydrogen 
remains  unburnt  and  no  oxygen  is  left  unused,  then 
this  combustion  will  take  place  in  that  peculiar  way 
described  as  explosive.  This  explosive  property  is 
possessed  by  a  substance  or  mixture  when  after  lighting 
it  at  one  spot  the  flame  will  itself  travel  quickly  through 
the  whole  mass.  A  room  filled  with  such  a  mixture 


146  POWER 

and  ignited  at  the  center  would  exhibit  a  beautiful 
phenomenon  if  it  could  be  observed  without  danger  ; 
the  flame  would  start  from  the  central  or  starting 
point  and  move  with  equal  speed  in  all  directions  so 
that  there  would  be  formed  a  true  ball  of  fire  rapidly 
increasing  in  size  until  all  the  mixture  had  been  burned. 
Of  course,  this  rapid  heating  would  raise  the  pressure, 
blowing  out  windows  and  possibly  also  the  walls,  as 
they  are  not  constructed  to  resist  such  pressure;  but  if 
carried  out  in  strong  iron  chambers,  the  only  effect 
would  be  a  mass  of  high-pressure  hot  gas  formed  in 
almost  the  wink  of  an  eye.  This  explosive  property 
is  peculiar  to  any  sort  of  intimate  mixture  of  fuel  and 
oxygen  if  the  proportions  are  right,  and  as  air  is  one- 
fifth  oxygen,  the  property  also  applies  to  any  intimate 
mixture  of  fuel  and  air.  It  makes  little  difference 
whether  the  fuel  be  in  the  form  of  fine  coal,  charcoal 
dust,  or  even  flour  dust,  fine  liquid  fuel  spray  such 
as  an  atomizer  may  produce,  or  a  combustible  gas 
such  as  is  used  for  lighting,  produced  in  any  convenient 
way,  or  the  vapor  of  a  liquid  fuel  such  as  might  be 
obtained  by  heating  gasolene.  In  every  case,  however, 
the  proportions  of  fuel  to  air  must  be  kept  within  proper 
limits.  It  is  explosive  mixtures  of  air  and  gaseous 
fuel,  or  air  and  oil  spray,  or  air  and  oil  vapor,  that  are 
now  used  in  gas  engines  to  produce  the  rapid  heating 
of  confined  gases,  and  these  gases  are  always  com- 
pressed in  cylinders  by  pistons  before  ignition,  the  hot 
high-pressure  gases  resulting  from  the  explosion  push- 
ing on  the  same  piston  to  do  the  work  on  the  return 
stroke. 

The  modern  gas-engine,  no   matter  whether  its  fuel 


MECHANISM  OF  GAS-POWER  147 

supply  be  primarily  gas,  oil,  or  coal,  will  involve  ap- 
paratus whose  principal  function  is  to  create  from  the 
fuel  as  it  exists  an  appropriate  explosive  mixture  for 
use  in  cylinders.  The  explosive  mixture  that  actually 
exists  in  the  gas-engine  cylinder  consists  of  air  mixed 
with  gaseous  fuel,  or  with  the  vapor  or  mist  of  liquid 
fuel,  in  certain  proportions,  with  which  active  mix- 
tures there  will  be  certain  neutral  substances  like  car- 
bonic acid  or  water  vapor  derived  from  a  previous 
explosion.  The  first  essential  process  in  the  operat- 
ing of  a  gas-engine  is,  then,  the  making  of  a  mixture  of 
appropriate  sort,  and  this  process  in  turn  involves  many 
secondary  processes,  some  of  which  will  be  traced, 
When  the  mixture  is  made,  it  must  be  introduced  into 
a  cylinder  and  there  treated  or  subjected  to  certain 
processes,  the  first  of  which  is  compression.  By  the 
movement  of  a  piston  the  mixture  is  forced  into  a 
small  space  at  one  end  of  the  cylinder,  causing  the  pres- 
sure to  rise,  and  at  some  high  compression  pressure, 
thus  developed  by  the  piston  alone,  the  fuel,  intimately 
mixed  with  all  the  air  it  needs  for  its  combustion  and 
no  more,  will  be  ignited  by  either  hot  metal  or  an 
electric  spark.  The  result  of  the  ignition  of  this  highly 
compressed  and  confined  explosive  charge  will  be  not 
a  noise,  not  a  disruption,  nothing  more  complicated 
than  a  rapid  heating  of  the  entire  mass  as  the  flame 
passes  through  it,  accompanied  by  a  rise  of  pressure. 
That  the  flame  will  pass  through  the  whole  mass  of 
the  confined  mixture  is  the  prime  characteristic  of 
explosive  mixtures,  whether  they  be  of  this  gas-engine 
sort  or  of  the  gunpowder  sort.  Gunpowder  is  a  mix- 
ture of  fuel  and  the  oxygen  it  needs  to  burn  it,  all  in 


148  POWER 

the  solid  form.  There  are  rapid-burning  powders 
and  slow-burning  powders,  and  we  have  learned  how 
to  apply  powder  of  varying  rates  of  combustion  to 
projectiles  of  different  weights,  sizes,  and  shapes,  to 
secure  the  most  effective  driving  of  the  projectile, 
by  giving  it  the  highest  muzzle  velocity  with  the  least 
tendency  to  smash  the  gun  or  to  dissipate  energy. 
Compared  with  most  gunpowder,  explosive  gaseous 
mixtures,  such  as  are  used  in  engines,  are  very  slow- 
burning  indeed;  and  the  rate  at  which  they  burn,  or 
the  rate  at  which  the  flame  travels  through  them  from 
particle  to  particle,  is  technically  called  the  rate  of 
propagation.  As  a  consequence  of  this  rapid  heating 
of  the  confined  gases,  the  pressure  very  materially 
rises  to  perhaps  twice  what  it  was  before,  occasionally 
4^  times,  rarely  5  times,  reaching  maximum  values  of 
from  150  to  600  pounds  per  square  inch,  and  the  ex- 
plosive combustion  has  performed  its  useful  function. 
The  explosive  combustion  has  rapidly  caused  the 
pressure  of  the  gases  to  double,  quadruple,  or  more,  and 
in  a  short  time  after  compression.  This  high  gas 
pressure  acts  on  the  same  piston  that  originally  com- 
pressed the  charge  into  the  confined  space,  technically 
called  the  cylinder  clearance,  or  explosion  chamber, 
or  breech  end.  On  the  return  stroke  following  com- 
pression, the  high-pressure  gases  will  drive  the  piston 
back,  and  in  so  doing  ever  so  much  more  work  will  be 
done  by  the  hot  gases  than  was  required  to  compress 
the  cold  gaseous  mixture,  and  the  difference  is  the 
useful  work.  The  burnt  gases,  when  the  piston  has 
reached  the  end  of  the  stroke,  must  be  expelled,  and 
the  whole  series  of  operations  of  making  the  mixture, 


MECHANISM   OF  GAS-POWER 


149 


introducing  it,  compressing,  exploding,  expanding,  and 
expelling  it  will  proceed  automatically  by  means  of 
mechanism  designed  with  this  end  in  view.  The  gas- 
engine  is  then  primarily  a  cylinder  with  a  piston  and 
certain  means  for  making  proper  mixtures,  getting 
them  into  the  cylinder,  treating  them  properly  after 
they  arrive,  getting  the  burnt  gases  out,  and  doing  it 


FIG.  129 

as  often  as  may  be  necessary,  as  fast  or  slow  as  may  be 
necessary,  and  using  as  much  mixture  as  may  be  neces- 
sary to  do  the  required  work.  There  must  also  be 
some  element  of  control,  so  that  if  much  work  is  required 
of  the  engine  much  work  will  be  done  on  the  piston 
by  the  use  of  much  mixture,  while  if  little  work  is  re- 
quired by  the  engine  only  a  little  mixture  will  be  used. 
Now  all  the  complicated  mechanisms  that  are  seen 


150 


POWER 


about  gas  engines,  and  which  are  well  indicated  by 
Fig.  129,  are  there  for  just  these  things,  as  well  as  per- 
haps for  a  few  others,  such  as  lubrication,  cooling  of 
the  hot  walls  to  prevent  them  twisting  out  of  shape 
and  to  prevent  the  lubricating  oil  from  burning  up, 
but  not  much  more.  It  is  hard  to  believe  that  there 
is  not  much  more  than  this  when  first  viewing  a  large 
gas-engine,  which  seems  to  be  a  mass  of  complicated 
parts,  the  duty  or  function  of  which  is  by  no  means 
clear  or  apparent. 

Before  proceeding  to  study  more  in  detail  the  ele- 
ments of  t|ie  essential  processes  of  making  mixtures 


FIG.  130 

from  natural  fuels,  proper  in  kind  and  amount,  it  will 
be  better  to  trace  the  succession  of  processes  most 
intimately  associated  with  the  cylinder,  piston,  and 
valves,  afterwards  returning  to  the  making  of  the  mix- 
ture before  it  reaches  the  cylinder. 

A  diagram  of  a  piston  and  two  valves,  one  for  ad- 
mission and  the  other  for  exhaust,  is  shown  in  Fig.  130. 
The  piston  is  attached  direct  to  the  usual  connecting 
rod,  crank,  crank-pin,  and  crank-shaft.  It  appears 
from  the  upper  left-hand  diagram  that  the  piston  is 
moving  outward,  drawing  the  mixture  into  the  cylinder 


MECHANISM   OF  GAS-POWER  151 

through  the  open  inlet  valve,  which  is  formed  much 
like  a  mushroom  and  is  called  a  poppet  valve.  Just 
how  the  proper  mixture  is  made  is  a  matter  of  no  im- 
portance at  this  time.  The  drawing  in  of  the  mixture 
occupies  the  whole  of  this  suction  or  charging  stroke. 
Under  the  influence  of  the  fly-wheel  the  piston  returns 
as  is  indicated  in  the  lower  left-hand  diagram,  com- 
pressing the  mixture  with  all  the  valves  closed.  This 
compression  continues  for  this  entire  stroke,  which  is, 
therefore,  called  the  compression  stroke,  and  at  the  end 
of  this  stroke  ignition  takes  place  with  a  resultant 
pressure  rise,  previously  described.  This  is  followed 
during  the  next  out  stroke  by  the  expansion  of  the  gases, 
as  shown  in  the  upper  right-hand  diagram,  all  valves 
still  remaining  closed  for  this  entire  expansion  stroke. 
Toward  the  end  of  this  expansion  stroke  the  exhaust 
valve  is  opened  and  the  gases  begin  to  rush  out.  The 
piston  then  returns,  expelling  the  rest  of  the  burnt 
gases  or  nearly  all  of  them,  through  the  exhaust  valve, 
which  is^open.  Of  course,  some  burnt  gases  must  be 
left  behind,  as  much  as  will  fill  the  explosion  chamber 
or  clearance  space.  Thus,  the  succession  of  processes 
occupies  four  strokes,  giving  to  such  an  engine  the  name 
of  four-stroke-cycle  or  four-cycle  engine,  which  may 
be  examined  again  with  a  little  more  detail  in  Fig.  131. 
Here  both  valves  have  vertical  stems.  A  water-jacket 
is  shown  surrounding  the  cylinder ;  a  more  usual  form 
of  piston  is  shown  with  the  pin  at  the  middle  of  its 
hollow  interior,  it  being  itself  a  cylinder  open  at  one 
end  and  closed  at  the  other.  The  diagram  shows 
eight  positions  of  the  piston  and  valves,  two  for  each 
stroke,  one  illustrating  the  relation  of  the  parts  at  the 


152 


POWER 


beginning  and  one  at  the  end.  Thus,  starting  at  the 
upper  left-hand  corner  and  passing  down,  the  suction 
stroke  is  shown  beginning  with  the  inlet  valve  open 
and  ending  with  it  closed,  the  valve  remaining  open 
all  the  intervening  time.  The  compression  stroke  is 


FIG.  131 

shown  with  both  valves  closed,  both  at  the  beginning 
and  end  and  for  all  the  time  between.  The  expan- 
sion stroke  is  shown  with  both  valves  still  closed  at 
the  beginning,  remaining  closed  until  the  crank  has 
reached  the  angle  shown,  at  which  point  the  valve  opens 
so  as  to  completely  relieve  the  cylinder  pressure  before 
the  piston  starts  back.  The  exhaust,  therefore,  really 


MECHANISM   OF  GAS-POWER 


153 


occupies  more  than  a  full  stroke  because  it  begins  before 
the  completion  of  this  remaining  part  of  the  expansion 
stroke  and  occupies  the  whole  of  the  next  stroke.  In 
still  greater  detail  some  of  the  mechanism  is  shown 
in  Fig.  132,  representing  a  cross-section  through  one 
of  these  four-cycle  horizontal  single-acting  engines. 
Here  it  appears  that  the  piston  has  webs  under  its  head 
to  strengthen  it.  It  has  spring  rings  around  part  of 


FIG.  132 

it,  so  formed  as  to  prevent  the  high-pressure  gases 
leaking  out.  There  is  water  all  around  the  cylinder 
and  around  the  valve  chambers.  The  valves  are  shown 
with  springs  to  close  them  and  keep  them  closed  all 
the  time  that  some  other  piece  of  mechanism  is  not 
pushing  them  open,  and  between  the  valves  is  shown 
the  igniter  at  F,  which  is  nothing  more  than  a  device 
for  making  an  electric  spark  at  the  proper  time  ;  besides 
these  features  there  are,  of  course,  a  frame,  crank, 
crank-shaft,  a  counterweight,  oil-cups,  oil  guards,  and 
fly-wheel.  A  small  vertical  high-speed  engine  is  shown 
in  Fig.  133,  in  which  there  is  the  usual  piston  with 
piston  rings,  two  valves,  one  above  the  other,  the  upper 


154 


POWER 


one  being  for  inlet  and  the  lower  one  for  exhaust,  both 
provided  with  springs  to  keep  them  closed,  but  the 
bottom  one  having  in  line  with  its  stem  a  push  rod 
against  which  a  cam  may  strike,  the  cam  being  only 
a  lump  on  the  small  auxiliary  shaft.  When  the  cam 
does  strike  the  push  rod,  it  will  rise  and  the  valve  will 
open.  Both  valves  might  be  so  operated,  and  in  most 

large  engines  are  operated  by 
such  cams,  but  in  some  small 
engines,  such  as  this,  to  simplify 
the  engine  the  inlet  valve  has 
no  cam  to  operate  it.  It  is 
just  held  to  its  seat  with  a 
light  spring.  When  the  pres- 
sure in  the  cylinder  due  to  the 
suction  stroke  of  the  piston 
becomes  less  than  atmosphere, 
or  less  than  in  the  mixture 
chamber,  that  difference  in 
pressure  on  the  two  sides  of 
the  valve  forces  the  valve 
open.  At  the  end  of  the  suc- 
tion stroke  the  difference  in 

pressure  is  relieved ;  in  fact,  it  would  reverse  on  com- 
pression so  that  the  valve  promptly  closes.  The  frame 
here  shown  is  of  different  form  from  the  previous  one, 
being  intended  for  attachment  to  the  frame  of  an  auto- 
mobile. The  cylinder  has  no  water-jacket,  but  has  in  its 
place  a  number  of  ribs.  The  heat  from  the  cylinder  will 
be  conducted  out  along  these  ribs  and  radiated  in  all 
directions  from  them ;  air  blast  fans  are  sometimes 
added  to  facilitate  the  cooling  of  these  ribs  and  the 


FIG.  133 


MECHANISM   OF  GAS-POWER 


155 


cylinder.  This  is  the  characteristic  of  the  air-cooled 
type  of  motor,  which  is  only  useful  in  small  sizes,  because 
even  the  most  effective  ribs  cannot  produce  good  enough 
cooling  for  large  cylinders ;  in  them  water  is  always 
used.  In  the  next  figure  (Fig.  134)  there  are  shown 
three  views  of  a  large  horizontal  engine  in  which  the 
operations  take  place  on  both  sides  of  the  piston, 


FIG.  134 

making  it  a  double-acting  engine.  The  piston  in  this 
case  is  fastened  to  a  piston  rod,  which  passes  through 
holes  in  the  heads  of  the  cylinders,  these  holes  being 
packed  by  stuffing  boxes  to  prevent  the  leakage  of  gas. 
Such  piston  rods  and  pistons  would  get  red-hot  in  a 
short  time  if  not  cooled,  as  explosions  take  place  regu- 
larly on  both  sides  of  them,  so  they  are  made  hollow 
and  water  is  circulated  through  them  just  as  water 


156 


POWER 


is  circulated  around  the  cylinders  and  valve  chambers. 
Valves  are  shown  as  in  the  previous  cases,  always  of 
the  poppet  form  and  moved  by  cams  through  rods  and 
levers.  Inlet  valves  are  on  the  top  and  exhausts  at 
the  bottom ;  but  here,  the  engine  being  double-acting, 
there  are  two  sets  of  valves,  one  for  each  end  of  the 
cylinder,  and  all  of  more  complicated  structure  to  give 
the  necessary  strength  and  avoid  cracking  from  the 
severe  internal  heat.  When  two  cylinders  are  set  in 


FIG.  135 

line,  the  engine  is  technically  known  as  a  tandem  double- 
acting  engine,  and  Fig.  135  illustrates  a  section  of  one 
of  these  engines  of  large  size,  the  piston  and  rod  of  one 
cylinder  being  also  shown  in  section  while  the  other 
is  not.  Two  sets  of  double-acting  cylinders,  side  by 
side,  and  working  on  the  same  crank-shaft,  constitute 
the  standard  arrangement  for  large  engines  and  is 
called  the  double-acting  tandem  twin  engine.  Two 


MECHANISM   OF  GAS-POWER 


157 


such  engines  of  about  1700  h.  p.  each  are  shown  in  Fig. 
136,  as  installed  in  the  power  plant  of  the  Milwaukee 


FIG.  136 

Railway.      A  closer  view  of   one  cylinder  of  another 

large  engine  of  this  type  is  shown  in  Fig.  137,  showing 

clearly  the  valve 

gear    and     the 

auxiliary      side 

shaft     from 

which  it  derives 

its  motion.     At 

the    new    steel 

plant  at  Gary, 

Indiana,     there 

will  be  provided 

over  a  hundred 

thousand  horse- 

-     ,1  FIG.  137 

power  of  these 

large  gas-engines,  one  group  of  which,  consisting  of  a 

row  of  three  thousand  horse-power  units,  is  shown  in 


158 


POWER 


Fig.  138.  The  man  standing  on  one  of  the  cylinders 
will  serve  as  a  scale  by  which  the  size  may  be  judged. 
All  of  these  engines  described  are  four-cycle  engines, 
that  is  to  say,  for  every  stroke  used  in  drawing  in  a 
charge,  three  other  complete  strokes  are  necessary, 
one  to  compress,  one  to  expand,  and  one  to  exhaust, 
so  that  with  such  large  double-acting  tandem  engines 
as  have  just  been  examined,  there  is  an  explosion  in 
each  chamber  every  fourth  stroke,  or  with  the  four 


FIG.  138 

chambers  of  a  double-acting  tandem  engine  each  stroke 
of  the  piston  is  a  working  stroke,  and  for  a  twin  engine 
there  will  be  two  impulses  forward  and  two  impulses 
back,  or  four  total  impulses  for  each  revolution  of  the 
fly-wheel. 

Engines  are  made  to  operate  under  other  cycles  so 
far  as  the  cylinder  functions  are  concerned.  For 
example,  Fig.  139  illustrates  an  engine  that  does  not 
have  as  many  valves  as  the  others  so  far  examined, 
but  it  has  something  in  place  of  them.  It  is  a  two-cycle 


MECHANISM  OF  GAS-POWER 


159 


engine,  so  called  because  it  can  carry  out  all  the  neces- 
sary series  of  cylinder  operations  in  two  strokes  instead 
of  four.  This  is  done  by  utilizing  the  other  end  of  the 
cylinder,  which  in  a  single-acting  four-cycle  engine  is 
idle,  or,  what  is  the  same  thing,  by  utilizing  a  closed 
crank  case,  or,  what  is  likewise  equivalent,  in  very  large 
engines  by  adding  pumps,  one  for  air  and  one  for  gas. 
The  function  of  these  pumps,  or  the  crank  case,  if  it  is 


FIG.  139 

closed,  or  the  forward  end  of  the  cylinder,  if  it  be  closed 
up,  is  to  get  ready  the  mixture  so  that  it  can  be  puffed 
into  the  cylinder  during  a  portion  of  the  stroke  with- 
out using  up  a  whole  stroke.  Referring  to  Fig.  139, 
it  will  appear  that  the  piston  is  fitted  with  a  lip  G, 
which,  in  the  position  shown,  is  just  underneath  a  slot 
or  port  in  the  cylinder  marked  /,  communicating  with 
the  passage  B,  C,  D  to  the  forward  end  of  the  cylinder 
and  communicating  likewise  at  the  bottom  of  B  with 
an  inlet  valve  A.  This  inlet  valve  is  of  the  automatic 


160  POWER 

sort,  having  no  cam  to  open  it.  Just  at  the  bottom 
of  the  cylinder  there  is  another  slot  E,  connecting 
with  the  exhaust  pipe.  Imagine  the  piston  to  move 
to  the  left,  then  whatever  is  in  the  cylinder  when  the 
piston  covers  the  ports  /  and  E  will  be  compressed. 
At  the  same  time  there  will  be  a  suction  in  the  cham- 
ber B  and  C,  lifting  the  valve  A  and  allowing  the  mix- 
ture to  follow  in  behind  the  piston  in  the  chamber  Z), 
while  the  compression  is  going  on  to  the  left.  When 
this  compression  is  all  over,  the  igniter,  placed  at  F, 
will  fire  the  charge,  the  piston  will  move  to  the  right, 
the  hot  gases  on  the  left-hand  side  expanding,  and 
compressing  the  mixture  on  the  right-hand  side.  When 
the  piston  has  reached  the  point  of  uncovering  E,  the 
high-pressure  hot  gases  will  rush  out  through  the  ex- 
haust pipe,  as  indicated  by  the  arrow.  Immediately 
after,  the  top  of  the  piston  will  uncover  the  port  7, 
communicating  with  the  fresh  mixture  at  J3,  which  will 
rush  in  because  it  is  compressed  and  the  pressure  in 
the  cylinder  is  now  low,  having  been  relieved  through 
E.  As  the  mixture  rushes  in  it  will  be  deflected  by 
G,  the  lip  on  the  piston,  and  will  so  be  deflected  sidewise 
to  the  end  of  the  cylinder  and  there  be  reflected  back 
towards  E,  pushing  out  in  this  way  much  of  the  burnt 
gases  that  may  be  left.  Thus,  exhaust  is  accomplished 
and  a  new  charge  fed  in  during  the  time  it  takes  for  the 
piston  to  uncover  the  port  E  and  get  back  again  so  as 
to  cover  it  up.  The  whole  working  series  of  operations 
is  accomplished  in  two  strokes,  which  fact  gives  the 
two-cycle  engine  its  name. 

All  modern  gas-engines  subject    the  mixture   after 
it  goes  to  the  cylinder  to  essentially  the  same  series 


MECHANISM   OF  GAS-POWER  161 

of  processes,  however  much  they  may  differ  in  other 
ways  structurally.  The  principal  differences  are  to 
be  found  in  the  means  for  making  the  mixture,  ad- 
justing the  quantity  of  mixture  needed  each  stroke, 
and  preparing  natural  fuels  by  vaporizing  liquids  and 
gasifying  coal.  The  first  vital  function  of  any  gas- 
engine  mechanism  is  to  make  proper  explosive  mix- 
tures, and  special  apparatus  is  designed  with  this  in 
view ;  for  the  mixture  is  to  the  gas-engine  what  the 
steam  pressure  is  to  the  steam-engine  and  the  water 
pressure  to  the  water-wheel.  Chemically  speaking,  a 
mixture  is  proper  when  it  contains  exactly  the  amount 
of  oxygen  necessary  to  burn  the  fuel,  no  more  and  no 
less,  and  when  at  the  same  time,  by  reason  of  perfect 
mingling,  each  particle  of  fuel  is  in  direct  contact  with 
its  own  share  of  oxygen.  Since  the  oxygen  must  be 
derived  from  the  air,  such  perfect  mixtures  cannot  be 
obtained,  because  each  particle  of  oxygen  carries  with 
it,  roughly,  five  times  its  own  amount  of  nitrogen,  which 
is  neutral  or  inactive.  The  effect  of  this  nitrogen  is 
not,  however,  serious,  as  it  only  retards  the  rate  of 
propagation  or  increases  the  time  of  explosion.  Much 
neutral  will  make  a  mixture  too  slow-burning  to  be  use- 
ful, but  fortunately  there  are  conditions  which  acceler- 
ate the  combustion  so  that  even  very  weak  mixtures 
are  still  useful  in  engines.  As  already  explained,  ex- 
plosive combustion  is  spherical  in  character,  inasmuch 
as  with  the  flame  moving  at  a  fixed  speed  in  all  direc- 
tions the  fire  exists  at  any  moment  on  the  surface  of 
a  sphere.  This  in  itself  results  in  accelerated  com- 
bustion, because  as  the  surface  of  a  sphere  grows 
faster  than  its  diameter,  more  mixture  will  be  burnt  at 

M 


162  POWER 


\ 


each  succeeding  moment  than  the  preceding,  even  if 
the  rate  of  propagation  or  increase  of  diameter  of  the 
sphere  is  constant. 

This  spherical  sort  of  regular  acceleration  of  the  rate 
of  combustion  is  of  great  importance  in  engines,  but 
the  uniform  flame  propagation  with  which  it  is  asso- 
ciated does  not  maintain  for  long.  There  is  an  even 
greater  tendency  to  accelerate,  due  to  the  elastic  nature 
of  gases.  It  is  plain  that  with  the  first  little  burst 
of  flame  the  pressure  will  momentarily  rise  at  that  spot 
higher  than  at  neighboring  spots,  and  so  a  sort  of  pres- 
sure impulse  or  wave  will  be  transmitted  through  the 
mass  much  as  sound  travels  through  the  air.  It  is 
found  in  actual  observations  on  mixtures  that  while 
at  first  the  flame  movement  seems  to  be  uniform,  it 
shortly  becomes  oscillatory.  This  may  be  due  to  the 
fact  that  in  mixtures  of  high  pressure  the  flame  travels 
faster,  so  that  at  the  crest  of  the  little  wave  started  from 
the  first  burst  of  flame  there  will  be  a  momentary  accel- 
eration of  combustion  followed  by  a  retardation  as 
the  crest  changes  into  a  hollow,  and  then  as  at  the  point 
where  a  hollow  existed  a  crest  appears,  there  will  be 
alternately  slow  and  fast  flame  movement.  The  wave 
thus  formed  will  meet  a  returning  wave,  a  wave  that  has 
been  sent  to  the  limits  of  the  chamber  and  reflected 
back.  It  seems  at  times  as  if  such  old  reflected  and  new 
advancing  waves  superimposed  their  crests,  producing 
localized  spots  of  very  high  pressure  and  very  fast  com- 
bustion. Such  localized  fast  combustion  is  detonating 
in  character  and  its  condition  is  designated  as  the 
explosive  or  detonating  wave. 

While  the  addition  of  neutral  to  a  mixture  will  cause 


MECHANISM   OF  GAS-POWER  163 

the  whole  combustion  to  proceed  more  slowly  and 
too  much  neutral  will  prevent  an  explosion  taking  place 
at  all,  yet  very  weak  mixture  can  be  successfully 
burned  at  a  proper  rate  by  previous  compression.  A 
mixture  so  weak  that  it  will  not  burn  in  the  open  air 
will,  if  compressed  enough,  burn  quite  readily,  so  that 
a  mixture  that  contains  so  much  neutral  as  to  be  non- 
explosive  may  be  made  explosive  if  it  is  previously 
compressed,  and  engines  may  successfully  use  gases 
so  weak  as  to  be  otherwise  useless. 

If  there  is  more  air  present  than  the  fuel  needs,  all 
the  excess  may  behave  the  same  as  a  neutral,  because 
it  is  inactive.  As  a  consequence,  mixtures  with  more 
air  than  is  chemically  needed  are  explosive,  as  well 
as  those  chemically  correct,  up  to  a  certain  limit,  of 
course.  On  the  other  hand,  mixtures  that  contain 
more  gas  than  the  air  present  can  burn  are  likewise 
explosive  up  to  another  limit,  the  extra  gas  behaving 
as  neutral  because  it  is  inactive.  Mixtures,  then,  may 
be  explosive  through  quite  a  wide  range  of  proportions 
of  air  to  fuel,  or  quite  a  wide  range  of  proportions  of 
active  and  inactive  diluent  materials.  The  range  of 
proportions  of  explosive  mixtures  is  greater  the  richer 
the  original  fuel.  Thus,  for  kerosene,  gasolene,  natural 
gas,  and  similar  rich  substances,  the  range  of  propor- 
tions of  air  to  fuel  is  very  great;  while  with  blast  furnace 
gas,  which  is  a  very  weak  gas,  the  range  is  not  so  great. 
In  every  case,  however,  the  range  of  explosive  propor- 
tions becomes  wider  and  wider  the  more  the  mixture 
is  compressed.  Whenever  fuel  is  in  excess,  it  is  entirely 
wasted,  but  excess  air  can  do  little  harm  if  the  mixture 
will  still  explode. 


164  POWER 

The  piston  speed  of  the  engine  is  zero  every  time  the 
piston  is  at  the  end  of  the  stroke,  because  it  comes  to 
a  dead  stop ;  the  speed  rises  to  a  maximum  somewhere 
about  mid  stroke  and  falls  again  to  zero,  so  that  it  is 
constantly  and  regularly  changing.  It  is  found  in  prac- 
tice that  the  best  results  are  obtained  when  the  com- 
bustion is  completed  as  nearly  as  possible  before  the 
piston  begins  its  working  stroke.  It  would  seem  from 
this  that  complete  combustion  should  take  place  be- 
tween the  time  when  compression  is  completed  and 
when  expansion  should  begin,  that  is  to  say,  it  would 
seem  as  if  the  explosion  should  be  completed  in  zero 
time  or  be  instantaneous.  Now,  as  a  matter  of  fact, 
the  conditions  are  not  quite  so  severe,  for  it  is  found 
that  by  igniting  the  charge  a  little  before  compression 
is  finished,  the  flame  acceleration  which  is  natural  to 
the  mixture  will  be  in  most  cases  quite  enough  to  prac- 
tically complete  the  combustion  before  the  expansion 
stroke  begins.  If  ignition  were  delayed  much,  the 
piston  speed  would  have  increased  so  much  that  in 
a  certain  sense  the  combustion  would  never  catch  up 
with  it,  and  instead  of  getting  high  explosion  pressures 
at  the  beginning  they  would  be  low ;  instead  of  getting 
most  work  from  the  heat  by  expanding  after  complete 
combustion,  there  would  be  obtained  a  less  amount  of 
work  because  expansion  would  be  proceeding  during 
combustion.  The  time  of  ignition,  therefore,  must 
be  carefully  adjusted,  first  with  respect  to  the  piston 
speed,  and  second  with  respect  to  the  natural  rate  of 
combustion  of  the  mixture.  A  mixture  which  is  too 
slow  burning  for  a  given  piston  speed  may  be  accel- 
erated by  increase  of  compression,  and  to  a  certain 


MECHANISM   OF  GAS-POWER  165 

extent  this  adjustment  can  be  made.  There  is,  how- 
ever, a  limit  to  this  increase  of  compression.  The  limit 
is  imposed  by  the  natural  temperature  of  ignition  of 
the  mixture.  As  the  mixture  is  more  and  more  com- 
pressed, so  does  it  become  hotter  throughout  its  entire 
mass;  sometimes  it  will  get  hot  enough  to  ignite  itself, 
independent  of  the  spark.  This  is  called  self-ignition 
or  preignition.  It  is  found  in  actual  work  that,  while 
a  weak  mixture  can  be  made  faster  burning  by  com- 
pression, it  cannot  be  made  as  fast  burning  as  a  rich 
mixture  because  the  compression  cannot  be  carried 
far  enough.  It  ignites  itself  before  as  much  compres- 
sion as  might  be  desired  has  been  attained. 

It  might  seem  from  these  arguments  that  it  was 
desirable  to  highly  compress  only  weak  mixtures  so 
as  to  make  them  burn  fast  enough,  but  as  a  matter  of 
fact  it  is  desirable  that  we  should  compress  all  mix- 
tures as  much  as  possible,  — •  as  much  as  the  tendency 
to  self-ignite  will  allow.  One  of  the  principal  proposi- 
tions concerning  engines  of  this  class,  solved  by  the 
mathematics  of  thermodynamics,  is  that  the  more  the 
compression  the  higher  the  efficiency  and  without 
limit.  An  engine,  then,  using  a  mixture  that  permits 
of  high  compression,  whether  it  be  rich  or  poor,  should 
by  reason  of  the  high  compression  alone  give  a  high 
efficiency,  and  within  certain  limits  this  is  found  to 
be  true  in  practice.  It  is  also  found  that  our  desire 
for  high  compressions  and  high  efficiency  is  limited 
only  by  the  temperature  of  ignition  for  the  mixture, 
and  in  general,  though  not  always,  the  richer  mixture 
will  stand  the  least  compression.  More  particularly 
is  it  true  that  certain  hydrocarbon  fuels,  such  as  kero- 


166  POWER 

:* 

sene  and  gasolene,  will  stand  the  least  compression 
before  ignition,  and  likewise  mixtures  with  free  hydro- 
gen will  stand  less  as  a  rule  than  mixtures  without 
hydrogen,  other  things  being  equal.  The  limit  of  com- 
pression, then,  is  set  in  practice  by  the  temperature  of 
ignition,  and  this  in  turn  depends  upon  the  nature  of 
the  fuel,  so  that  with  different  fuels  it  is  not  possible 
to  get  quite  the  same  efficiency,  because  equally  high 
compressions  are  not  permissible. 

So  far  as  the  engines  themselves  are  concerned,  these 
physical  properties  of  explosive  mixtures  are  valuable 
in  two  ways:  first,  in  dictating  how  the  mixtures 
may  be  treated  in  cylinders ;  and  second,  in  explaining 
things  which  happen  but  which  were  not  foreseen.  A 
knowledge  of  such  mixtures  is  quite  essential  to  a  correct 
understanding  of  the  gas-engine.  We  are,  however, 
concerned  principally  with  one  part  of  the  application 
of  this  subject.  The  engine  will  run  properly  and  best 
when  its  mixture  is  most  constant,  when  the  engine 
gets  the  proper  quantity  of  this  mixture,  and  when  the 
mixture  received  is  compressed  as  highly  as  possible 
without  forcing  it  beyond  control. 

As  previously  stated,  by  far  the  greatest  variation 
in  the  mechanism  of  engines,  and  by  far  the  greatest 
complication  in  their  mechanism,  is  found  in  that  part 
of  the  valve  gear  which  is  concerned  with  the  propor- 
tioning of  mixtures,  the  actual  mingling  of  the  parts  of 
the  mixture,  and  with  the  adjustment  of  the  quantity 
in  proportion  to  the  work  to  be  done. 

Mixtures  are  proportioned  in  engines  as  they  are 
drawn  in.  In  other  words,  they  are  proportioned  as 
they  are  made.  The  suction  stroke  of  the  piston  starts 


MECHANISM   OF  GAS-POWER 


167 


a  movement  of  gases  towards  the  cylinder,  and  as  there 
will  be  two  sources  from  which  to  satisfy  this  displace- 
ment, one  the  atmospheric  air  and  the  other  the  fuel 
gas-pipe,  it  is  plain  that  if  a  valve  in  the  fuel  gas-pipe 
be  closed  and  the  air  opening  be  free,  nothing  but  air 
will  enter;  or  if  the  air  valve  be  closed  and  the  gas 
valve  opened,  nothing  but  gas  will  enter;  and  so  if  a  valve 
be  opened  in  both  the  air  and  the  gas  ports,  both  air 
and  gas  will  enter  and  the  proportions  will  depend  upon 
the  relative  openings.  This  is 
the  primary  principle  of  pro- 
portioning used,  two  openings, 
one  for  air  and  the  other  for 
gas,  and  means  for  adjusting 
these  openings  so  that  the  rela- 
tive amount  of  air  and  gas  can 
be  adjusted.  These  valves  for 
adjusting  the  proportions  are 
generally  independent  of  the 
valve  controlling  the  mixture 
admission  to  the  cylinder,  and 
may  themselves  or  in  conjunc- 
tion with  some  other  device  be  called  the  mixing  valves 
or  proportioning  valves  of  the  engine.  In  Fig.  140  is 
shown  an  inlet  valve  attached  to  the  cylinder  casing, 
with  gas  and  air  ports,  the  upper  one  being  for  gas, 
each  port  provided  with  a  damper  valve.  On  the 
suction  stroke  of  the  engine  the  sliding  sleeve  attached 
to  the  valve  stem  will  be  pushed  down  with  the  valve, 
and  the  holes  in  the  casing  and  sleeve  will  register. 
In  this  position  the  gas  drawn  past  its  damper  will 
pass  through  the  port  from  the  inner  to  the  outer 


FIG.  140 


168 


POWER 


chamber,  meeting  air  from  the  other  port,  and  the  mix- 
ture will  enter  the  cylinder  by  passing  the  poppet 
valve.  This  sliding  sleeve  is  added  to  the  inlet  valve 
stem  to  prevent  the  ga&,  which  is  generally  under  some 
pressure  higher  than  atmosphere,  from  flowing  into  the 
air  passage  when  the  piston  suction  ceases  between 
changing  strokes.  If  this  were  omitted,  there  would 
be  a  tendency  for  the  mixture  to  become  too  rich  at 

low  loads  or  at  intervals 
between  suctions,  be- 
cause gas  would  collect 
in  the  air  passage.  This 
slide,  therefore,  serves 
to  overcome  this  ten- 
dency of  the  gas  to  catch 
up  on  the  air  by  reason 
of  different  pressures. 

As  the  atmospheric 
air  has  no  tendency  to 
flow  except  during  suc- 
tion, the  air  damper 
valve  might  be  done 
away  with  and  in  many  engines  actually  does  not  exist. 
Similarly,  the  slide  attached  to  the  valve  stem  to 
prevent  the  gas  flowing  over  to  the  air  passage  is  often 
omitted,  but  other  devices  are  substituted  in  its  place. 
In  Fig.  141  is  shown  a  mixing  valve  of  a  different  sort, 
forming  part  of  the  main  inlet  valve,  a  second  disk 
attached  to  the  main  valve-stem  opening  and  closing 
the  gas  passage.  These  latter  mixing  valves  are  all 
mechanically  opened  and  closed,  whether  attached  to 
the  main  valve-stems  or  independent,  whereas  some  of 


FIG.  141 


MECHANISM   OF  GAS-POWER 


169 


the  good  mixing  valves  of  the  independent  class  are 
automatic.  One  of  this  kind,  shown  in  Fig.  142,  is  a 
sort  of  check- valve  arrangement.  Any  reduction  of 
pressure  in  the  upper  chamber  m  and  T  lifts  the  peculiar 
shaped  check-valve  which  has  two  seats  a  and  g,  so  that 
gas  passes  out  into  the  reduced  pressure  mixing  cham- 
ber from  the  gas-pipe  through  port  g}  at  the  same 
time  that  air  passes  up 
through  slot  a,  the  two 
streams  crossing  and  so 
mixing.  Later,  by  pass- 
ing upward  through 
other  slots  m,  the  air 
and  gas  are  further 
mixed  or  stirred.  In 
the  mixture  chamber 
there  is  a  damper  con- 
trol valve  T  to  fix  the 
amount  of  mixture  that 
may  reach  the  engine. 
The  relative  advantages 
of  all  these  ways  of 
making  mixtures  and 
proportioning  them,  together  with  perhaps  hundreds 
of  other  different  ones  in  use,  are,  of  course,  beyond 
the  province  of  such  lectures  as  this.  The  examples 
shown  will  serve  as  an  indication  of  the  guiding  prin- 
ciples used  to  carry  out  the  functions  of  mixing  and 
proportioning,  which  are  of  prime  importance.  It  is 
a  fact  that  the  success  of  gas-engines,  especially  large 
ones,  depends  very  largely  upon  the  perfection  with 
which  the  details  of  these  devices  are  worked  out. 


FIG.  142 


170  POWER 

When  the  proper  sort  of  mixture  is  made  by  means 
such  as  have  been  examined,  the  next  thing  necessary 
is  to  adjust  the  quantity  of  mixture  that  the  engine 
may  receive.  From  the  last  figure  it  appeared  that 
there  was  a  damper  valve  between  the  mixing  valve 
and  the  main  inlet  valve.  This  is  one  of  the  simplest 
and  most  effective  means  of  controlling  the  quantity 
of  mixture.  The  main  inlet  valve  is  opened  the  same 
amount  every  time  by  the  mechanism,  but  the  engine 
can  get  no  mixture  if  this  damper  is  shut ;  if  it  is  opened 
wide,  a  full  charge  will  be  taken.  The  amount  of  this 
damper  opening  is,  therefore,  a  measure  of  the  quantity 
of  mixture  the  engine  can  get,  while  the  mixing  valve 
makes  automatically  as  much  as  is  required,  and  of  the 
proper  kind.  It  is  the  function  of  the  governor  of  the 
engine  to  fix  the  position  of  this  damper.  At  light 
loads  the  speed  rises  and  certain  free  weights  of  the 
governor  move,  fly  out,  and  actuate  the  damper  through 
rods,  moving  it  to  the  closed  position.  At  heavy 
loads  the  speed  reduction  moves  it  to  the  open  posi- 
tion and  such  sensitiveness  can  be  secured  as  is 
surprising  to  a  stranger.  This  device  is  an  example 
of  the  principle  of  controlling  the  quantity  of  mixture 
by  a  throttle  valve,  independent  of  both  the  mixing 
valve  and  of  the  main  inlet  valve.  There  are  other 
ways  of  doing  the  same  thing,  and  many  of  them, 
and  one  or  two  examples  of  typical  methods  will  be 
illustrated. 

Instead  of  having  a  mixture  control  valve,  or  throttle 
valve,  between  the  mixing  valve  and  the  main  inlet 
valve,  and  all  three  independent,  the  throttle  effect 
can  be  secured  at  the  main  inlet  valve  by  varying  the 


MECHANISM   OF  GAS-POWER 


171 


lift  of  that  valve,  at  light  loads  letting  it  open  just 
a  little,  and  at  full  loads  permitting  full  movement, 
as  controlled  by  the  governor.  Such  a  device  is  shown 
in  Fig.  143.  The  cam  shaft  is  shown  at  the  side  carry- 
ing a  cam  which  strikes  the  roller,  and  through  a  guided 
push  rod  causes  the  lever  L  to  move  upward.  The 
other  end  of  the  lever  L  at  the  left  is  fixed  to  the  valve- 
stem  by  a  pin  shown  at  £,  and  on  the  top  this  lever  is 
curved  to  an  arc  of  a  circle,  having  its  center  at  2. 
Along  this  curved  portion  may 
be  swung  the  shaded  point 
attached  to  the  bell-crank. 
This  point  is  the  fulcrum  of 
the  lever  L.  When  the  point 
of  the  fulcrum  is  close  to  the 
valve-stem,  that  is  to  say,  at 
the  left,  the  constant  lift  of  the 
outer  end  of  the  cam  will  move 
the  valve  but  little,  whereas  if 
the  lever  point  is  at  the  outer 
end  of  L,  the  valve  will  move  a  good  deal.  The  gov- 
ernor shown  above  the  cam  fixes  the  position  of  this 
movable  fulcrum  so  that  at  high  speeds  it  is  in  one 
position,  and  at  lower  speeds  in  another  position,  thus 
varying  the  quantity  of  the  mixture  by  varying  the 
extent  of  the  main  valve  lift  through  which  all  mixture 
must  pass.  This  is  known  as  the  variable  lift  inlet 
valve  type  of  mixture  control,  independent  of  the 
mixing  valve.  Another  type  controls  the  quantity 
of  mixture  at  the  mixing  valve  itself,  independent  of 
the  main  valve  and  with  no  separate  throttle.  Such 
a  device  is  shown  in  Fig.  144.  Here  the  governor 


FIG.  143 


172 


POWER 


H, 


moves  a  cylindrical  sleeve  up  and  down,  thus  varying  the 
opening  of  the  slots  in  the  sleeve  A,  which  communicate 
with  the  air  and  gas  passages  C  and  D.  This  up-and- 
down  sleeve  movement  will  close  both  air  and  gas  pas- 
sages at  the  same  time  and  in  proportion,  independent 
of  the  main  inlet  valve.  It  is  the  function  of  the  gov- 
ernor to  fix  the  vertical  position  of  this  sleeve,  which 

will,  therefore,  have  a 
position  for  each  speed 
and  remain  there  until 
the  speed  changes. 

There  are  several  hun- 
dred different  systems 
for  controlling  the  quan- 
tity of  mixture  admitted 
to  the  cylinder  while 
maintaining  its  quality 
constant,  and  others  for 
varying  the  quality  in- 
tentionally, with  all  con- 
F  ^  ceivable  combinations 

of  these  functions  .of 
making  mixtures  and  admitting  them  to  the  main 
cylinder;  but  from  what  has  been  said  the  nature  of 
the  problem  should  be  clear. 

In  all  modern  engines  the  mixture  that  is  formed, 
admitted,  and  compressed  is  ignited  by  electric  sparks 
except  in  a  few  types  of  oil  engines  that  will  be  dis- 
cussed later.  These  electric  sparking  arrangements 
are  of  two  general  classes,  but  all  have  the  same  effect. 
In  the  class  known  as  the  make-and-break  spark  two 
metal  parts  are  brought  together  within  the  cylinder 


MECHANISM  OF  GAS-POWER  173 

so  that  an  electric  current,  generated  either  by  batteries 
or  little  dynamos  outside,  may  flow  through  the  point 
of  contact.  When  the  point  of  contact  is  broken,  the 
electric  current,  especially  if  it  is  assisted  by  a  coil,  the 
details  of  which  need  not  be  described  here,  will  not 
immediately  cease  flowing,  but  will  have  a  tendency 
to  jump  the  gap,  forming  a  little  stream  of  flame,  which 
will,  of  course,  break  off  when  the  gap  gets  wide  enough. 
The  best  practical  illustration  of  this  action  is  the  or- 
dinary arc  light  used  in  the  streets  for  illumination. 
Here  the  two  parts  are  carbon  pencils  which  originally 
rest  together  in  contact,  but  when  the  current  flows 
through  them  they  are  drawn  apart  by  means  of  mecha- 
nism in  the  body  of  the  lamp  and  maintained  at  a  cer- 
tain distance  so  that  the  electric  flame  or  arc  can 
continue  to  pass.  In  the  gas-engine  igniter  of  the  make- 
and-break  type,  metal  parts  are  used  in  place  of  these 
carbons  and  are  brought  together  and  sprung  apart  at 
the  proper  point  of  the  stroke  by  suitable  mechanisms. 
This  short  electric  flame  or  arc  ignites  the  mix- 
ture in  contact,  after  which  its  own  property  of  self- 
propagation  will  suffice  to  inflame  the  whole  mass. 
In  the  other  system  of  ignition  two  fixed  points,  both 
of  metal,  are  used,  projecting  into  the  cylinder.  Cur- 
rent of  very  high  electrical  pressure  or  voltage  is  led 
to  these  two  fixed  points,  the  ends  of  which  are  separated 
only  about  TV  inch.  When  the  electrical  pressure 
is  high  enough,  the  current  will  jump  the  intervening 
space  and  thus  make  a  sudden  flash.  This  is  known 
as  the  jump  spark  system  and  a  common  illustration 
of  jump  sparks  is  lightning.  The  jump  spark  is  really 
nothing  more  than  a  little  flash  of  lightning,  differing 


174  POWER 

from  it  only  in  the  fact  that  its  path  and  the  time  when 
it  is  to  pass  are  also  controlled  mechanically. 

This  review  of  the  principal  processes  underlying 
the  obtaining  of  power  by  the  explosion  of  gaseous  fuel 
and  air  mixtures  has  been  based  more  on  the  ideas 
involved  than  on  the  mechanism  because,  as  was  the 
case  with  the  steam-power  system,  the  mechanism  may 
have  great  variety  of  form  and  detail  and  still  be  essen- 
tially the  same  in  what  it  is  able  to  do.  By  these 
processes,  embodying  any  one  of  the  standard  forms 
of  mechanism,  it  appears  that  we  are  able  to  transform 
the  heat  of  combustion  almost  instantly  into  useful 
work,  or  at  least  part  of  it.  Both  combustion  and 
work  generation  take  place  within  the  same  cylinder 
chamber,  and  the  second  immediately  follows  the  first. 
There  is  no  intermediate  substance  introduced,  like 
water  and  steam  as  in  the  earlier  systems,  involving 
losses  of  heat  in  making  the  steam  and  controlling  its 
flow.  Such  losses  as  occur  take  place  right  in  the  same 
chamber  where  everything  else  happens.  By  means  of 
this  direct  procedure,  and  it  is  to  the  method  that  at- 
tention should  be  directed,  it  is  possible  to  transform 
more  of  the  heat  of  combustion  into  work  than  by  using 
steam  between  the  fire  and  actual  working  chamber,  so 
that  gas-engines  are  essentially  capable  of  higher  thermal 
efficiency  than  steam  plants.  Cases  are  on  record  in 
which  there  was  generated  into  work  over  30  per  cent 
of  the  heat  of  the  fuel,  about  twice  what  our  best 
steam-engines  are  capable  of  doing,  and  it  is  a  common 
every-day  practice  to  secure  efficiencies  of  from  25  to  30 
per  cent.  Of  course,  it  must  be  remembered  that  the 
gas-engine  cannot  do  this  unless  the  fuel  is  in  the  proper 


MECHANISM   OF  GAS-POWER  175 

gaseous  or  equivalent  form,  and  coal  is  not  in  that 
form  naturally.  When  coal  is  transformed  from  its 
solid,  natural  condition  to  the  gaseous  form,  a  perfectly 
feasible  process,  there  will  be  involved  a  loss,  so  that 
when  gas-engines  are  to  operate  on  coal  fuel  something 
must  be  subtracted  from  these  efficiencies,  but  not  a 
great  deal.  Another  very  remarkable  fact  concerning 
the  efficiencies  of  these  engines,  which  must  not  be  for- 
gotten, is  that  the  little  engine  of  25  h.  p.  has  almost 
as  high  an  efficiency  as  the  large  ones  of  2500  h.  p. 
This  is  another  striking  contrast  to  steam-engine  per- 
formance, in  which  to  get  a  high  efficiency  the  engine 
must  be  large.  It  has  already  been  pointed  out  that 
the  average  horse-powers  of  engines  used  in  manu- 
facturing operations  is  small,  less  than  100.  In  such 
sizes  these  gas-engines  are  ever  so  much  more  efficient 
than  steam-engines,  being  built  to  convert  from  two 
to  four  times  as  much  of  the  heat  of  the  fuel  into  work 
as  the  corresponding  steam-engine  can  do.  It,  there- 
fore, seems  reasonable  to  expect  that,  as  the  use  of  these 
gas-engines  becomes  wider  as  they  become  better 
known,  there  will  result  for  the  general  average  of 
conditions  throughout  the  country  a  very  material 
reduction  in  fuel  consumption  for  the  same  power, 
or  a  large  extension  of  the  total  power  for  no  increase 
in  fuel  consumption.  They,  therefore,  are  likely  to 
be  found  the  greatest  fuel  conservation  means  that  the 
country  has  yet  seen.  Their  construction  and  ex- 
tended use  may  be  expected  to  improve  with  time, 
and  their  reliability  of  operation  and  popularity  with 
power  users  will  depend  upon  the  perfection  with  which 
their  details  are  worked  out  structurally.  The  struc- 


176  POWER 

tural  developments  which  have  led  to  the  modern 
gas-engines  are  scarcely  10  or  15  years  old.  Much 
more  may  we  expect  of  the  system  when  it  has  been 
in  use  for  160  years,  which  is  the  case  with  the  steam- 
engine.  No  one  familiar  with  the  subject  would  dare 
to  predict  the  possibilities,  but  that  great  progress  will 
be  made  is  absolutely  certain. 


VI 


ADAPTATION     OF     SOLID     AND     LIQUID     FUELS     FOR     THE 
USE    OF   INTERNAL    COMBUSTION    ENGINES 

ALL  early  gas  engines  were  operated  on  illuminating 
gas  used  as  a  fuel,  so  that  their  use  was  confined  to  cities 
where  such  gas  was  available ;  and  the  sizes  that  could 
be  economically  so  operated  were  limited  also,  because 
this  kind  of  fuel  is  very  expensive.  To  illustrate  this 
latter  point,  assume  that  illuminating  gas  is  sold  at 
$1  per  1000  cubic  feet,  each  cubic  foot  yielding  on 
combustion  600  heat  units.  Under  these  conditions 
the  purchaser  receives  for  his  dollar  600,000  heat  units. 
Compare  this  now  with  bituminous  coal  at  $3  per  ton 
of  2000  pounds,  each  pound  yielding  about  15,000 
heat  units,  thus  giving  to  the  purchaser  30,000,000 
heat  units  for  $3  or  10,000,000  for  one  dollar.  Under 
these  conditions  it  appears  that  such  gas  fuel  is  nearly 
17  times  as  costly  as  the  coal,  so  that  power  users  can- 
not afford  to  use  such  gas  in  competition  with  this  coal 
unless  there  is  a  corresponding  difference  in  the  amount 
of  heat  that  can  be  converted  into  useful  work  in  favor 
of  the  gas.  In  other  w^ords,  unless  a  gas-engine  using 
this  fuel  is  capable  of  transforming  into  work  17  times 
as  much  of  the  heat  it  gets  in  the  gas  form  as  a  steam 
power  system  can  convert  from  the  heat  in  coal  form, 
there  would  be  no  advantage  in  the  use  of  gas-engines. 
Enormous  as  this  difference  may  seem,  fully  this  much 
N  177 


178  POWER 

exists  when  the  units  are  very  small,  a  few  horse-power, 
for  example,  so  that  in  installations  requiring  only  a 
few  horse-power  it  is  found  to  be  more  economical  to 
use  a  small  gas-engine  even  with  the  expensive  illumi- 
nating gas  fuel  than  to  use  the  same  size  of  steam-engine 
with  the  cheaper  fuel.  This  situation  is  helped  by  the 
lower  first  cost  of  a  small  gas-engine  compared  with 
the  same  capacity  of  steam-engine  and  boiler  together. 
When,  however,  the  size  of  the  unit  increases  to  several 
hundred  horse-power  the  situation  is  quite  different. 
In  these  sizes  illuminating  gas  as  fuel  can  never  com- 
pete with  coal  used  directly. 

If  other  and  cheaper  sources  of  gas  supply,  or  means 
of  adapting  coal  and  oil  fuels  for  the  use  of  gas-engines, 
had  not  been  discovered,  the  gas  system  of  power  gen- 
eration, in  spite  of  its  inherently  higher  possible  effi- 
ciency, could  never  have  competed  with  the  steam 
system  in  the  larger  sizes.  In  the  development  of  the 
gas-engine  mechanism  up  to  the  time  when  it  had  been 
demonstrated  that  it  was  a  commercial  machine,  two 
sources  of  cheaper  gas  appeared.  The  first  was  the 
natural  gas  which  issues  from  the  earth,  but  in  only  a 
few  localities,  the  most  notable  of  which  are  the  middle 
Central  States,  Pennsylvania,  Ohio,  Illinois,  Indiana, 
and  West  Virginia.  This  fuel  is  ideal  and  in  some 
places  can  be  produced  and  sold  as  low  as  5  cents  per  1000 
cubic  feet.  As  this  gas  yields  about  1000  heat-units  per 
cubic  foot,  this  price  is  equivalent  to  5  cents  per  1,000,000 
heat-units,  or  20,000,000  heat-units  for  SI,  a  decidedly 
cheap  fuel  for  use  in  gas-engines,  when  it  is  considered 
that  these  engines  can  convert  into  useful  work  25  or 
30  per  cent  of  the  heat  in  the  gas.  One  other  source 


ADAPTATION   OF  FUELS  179 

of  cheap  gas  supply  is  the  blast-furnace  in  which  iron 
ore  is  converted  into  pig-iron.  To  these  furnaces, 
which  are  almost  the  same  in  general  character  as  tall 
chimneys,  alternate  layers  of  coke,  iron  ore,  and  lime- 
stone, in  measured  quantities,  are  fed  at  the  top  ; 
heated  air  is  blown  into  the  bottom  and  the  whole 
interior  becomes  a  white-hot  mass.  The  heat  causes 
the  limestone  to  combine  with  the  rock  which  binds 
the  iron  in  the  ore  form,  thus  setting  free  metallic  iron, 
all  through  the  influence  of  the  heat  of  combustion  of 
the  coke.  From  the  top  of  the  furnace  there  is  dis- 
charged a  rather  weak  but  combustible  and  useful 
gas,  which  is  mainly  nitrogen  from  the  air,  about  70 
per  cent.  The  other  30  per  cent  is  principally  carbon 
monoxide  gas,  which  is  the  result  of  combining  one 
particle  of  carbon  with  one  particle  of  oxygen,  and 
which  is  combustible  when  one  particle  of  the  gas  takes 
up  another  particle  of  oxygen.  This  combustible  gas, 
always  consumed  in  stoves,  is  used  to  heat  the  air-blast, 
and  under  boilers  to  make  steam,  the  steam  being  used 
to  run  blowing  engines  to  supply  the  air  which  the  fur- 
nace requires.  This  gas-generated  steam  is  also  used 
to  supply  power  for  rolling  the  iron  into  bars,  operat- 
ing hoists,  pumping  water  for  electric  light,  and  a 
variety  of  other  purposes.  When  the  gas-engine  ap- 
peared, this  same  gas  was  burnt  directly  in  cylinders, 
yielding  twice  as  much  power  as  before,  making  avail- 
able for  sale  an  amount  of  power  equal  to  what  the 
small  plant  itself  used.  Each  blast-furnace,  more 
especially  in  Germany,  where  questions  of  economy 
receive  most  attention,  became  then  a  source  of  power 
for  the  community,  much  the  same  as  a  waterfall. 


180  POWER 

Because  the  gas-engine  is  able  to  convert  so  much  more 
of  the  heat  of  the  blast-furnace  gas  into  work  than  the 
steam-engine  it  displaced,  the  work  of  the  plant  was 
done  as  before,  and  about  an  equal  amount  of  power 
was  left  over  to  be  sold  to  neighboring  factories,  to 
operate  street  railways,  and  to  light  neighboring  towns. 
The  really  important  developments,  however,  were 
not  possible  without  the  adaptation  of  the  more  common 
natural  fuels,  oil  and  coal,  and  this  adaptation  has  now 
been  carried  to  fair  success,  though  much  improve- 
ment is  yet  to  be  accomplished.  To  understand  the 
apparatus  by  which  coal  and  oil  are  rendered  available 
for  gas-engines,  requires,  first,  an  understanding  of  the 
peculiarities  of  the  fuels  themselves.  Perhaps  the 
earliest  attempts  to  get  a  combustible  gas  from  coal 
involved  the  use  of  roasting  processes,  of  which  there 
are  two  important  classes:  one  in  which  the  gas  that 
is  driven  off  in  baking  is  wanted,  and  the  other  in  which 
the  residue  or  coke  is  wanted ;  in  either  case  the  other 
product  is  considered  a  waste  or  by-product.  In  the 
making  of  coke  from  bituminous  coal  the  standard 
method  for  a  great  many  years  has  been  to  put  a  layer 
of  crushed  material  in  the  bottom  of  a  circular  chamber, 
having  an  arched  roof  and  more  or  less  resembling  a 
beehive,  as  shown  in  Fig.  145,  and  hence  called  a  bee- 
hive oven.  This  coal  is  ignited  from  the  top  and 
side,  and  air  is  allowed  to  enter  the  first  door  slowly. 
The  heat,  driving  off  the  gas  which  the  coal  yields  by 
the  roasting  process,  is  derived  from  slowly  burning  the 
former  in  the  upper  part  of  the  domelike  chamber 
until  the  whole  bed  has  been  equally  roasted.  In  these 
beehive  ovens  the  flame  and  burnt  gases  escape  from 


ADAPTATION  OF  FUELS 


181 


the  top  through  a  hole.  The  coke  which  is  left,  and 
which  weighs  about  50  or  60  per  cent  of  the  original 
coal,  is  drawn  out  and  used  in  blast-furnaces  where  coke 
is  needed;  but  in  the  formation  of  the  coke  a  peculiar 
thing  happens.  At  a  certain  stage  of  the  heating  the 
whole  mass  may  be  said  to  be  practically  melted,  each 
small  particle  of  the  original  coal  entirely  losing  its 
identity  and  merging  with  the  rest,  much  the  same  as 
broken  molasses  candy  will  melt  together  in  hot  weather. 


FIG.  145 


From  the  molten  mass  gas  continuously  escaping 
punctures  it  full  of  holes,  and  in  time,  the  gas  being  all 
driven  off,  the  rest  of  the  mass  solidifies  into  a  single 
piece  of  hard,  porous  coke.  It  would  be  a  single  piece 
if  the  mass  did  not  shrink  in  the  process,  but  it  does 
shrink,  producing  a  series  of  fissures  or  cracks,  so  that 
the  coke  consists  of  large  pieces,  sometimes  as  large 
as  a  man's  body,  but  generally  smaller,  bearing  no 
resemblance  whatever  to  the  original  shape  or  size  of 
the  particles  of  coal  from  which  it  was  made.  This 
beehive  oven  method  of  roasting  coal  produces  gas 


182 


POWER 


which  is  allowed  to  go  to  waste,  the  heat  of  which  is 
partly  used  to  maintain  the  temperature  for  the  rest 
of  the  process.  Thus,  gas  is  the  waste  material  and 
coke  the  desired  product. 

An  almost  exactly  similar  process  of  roasting  is 
carried  out  in  the  manufacture  of  coal-gas,  one  kind 
of  illuminating  gas,  in  which  gas  is  the  desired  product 


FIG.  146 

and  the  coke  the  waste  product.  In  this  system  coal 
is  fed  to  earthenware  chambers  open  at  one  end  and 
closed  at  the  other,  called  retorts,  shown  in  Fig.  146 ; 
a  number  of  them,  in  this  case  nine,  being  placed  side 
by  side  in  the  same  brick  setting  and  a  fire  maintained 
below  to  heat  them  from  the  outside.  The  heat  from 
the  fire  below  roasts  the  coal  in  the  retorts,  driving  off 
the  gas,  which  is  caught,  and  after  purification  is 
finally  pumped  through  pipes  in  the  streets  of  cities 


ADAPTATION   OF   FUELS  183 

for  illumination,  for  gas-stoves  or  small  gas-engines. 
After  the  roasting  has  proceeded  for  a  time  sufficient 
to  drive  off  all  the  gas,  the  coke  that  is  left  is  drawn 
out  and  sold,  a  large  part  going  to  bakers  for  their 
ovens. 

In  these  coal-roasting  processes  there  is  driven  off 
from  the  coke  what  we  are  pleased  to  call  gas.  It  is, 
however,  a  most  complex  mixture  of  gases  and  vapor- 
ized liquids,  consisting  of  various  compounds  of  car- 
bon, hydrogen,  oxygen,  and  nitrogen,  with  occasionally 
some  sulphur.  As  carbon  and  hydrogen  are  the  main 
fuel  constituents,  it  is  very  common  to  regard  all  these 
distillation  substances  as  hydrocarbons,  and  these 
hydrocarbons  are  all  in  the  gaseous  form  as  driven  off 
because  they  are  very  hot  at  that  time.  When  they 
are  cooled,  however,  it  is  discovered  that  some  of  them 
will  condense  into  viscous  or  thick  liquids  of  bad  smell 
and  brownish  black  in  color.  These  are  called  by  the 
general  name  of  gas-tar,  coal-tar,  or  just  "tar,"  and  it  is 
this  tar  which  is  responsible  for  the  melting  previously 
referred  to. 

The  adaptation  of  coal  for  gas-engine  purposes 
should  leave  no  by-products.  All  the  coal  should  be 
converted  into  gas,  so  that  mere  roasting  is  not  sufficient, 
for  even  though  it  yields  a  gas  there  is  also  left  over  the 
coke,  and  means  must  be  found  for  gasifying  this  coke, 
which  means  will  also  be  found  to  serve  for  the  gasi- 
fying of  anthracite  coals,  which  themselves  yield  little 
or  no  gas  on  roasting. 

The  process  by  which  coke  or  anthracite  coal  may 
be  completely  gasified  involves  no  such  simple  treat- 
ment as  roasting,  but  chemical  combination  of  the 


184  POWER 

carbon,  which  is  the  main  constituent  of  both  these 
fuels,  with  oxygen  of  the  air,  much  the  same  in  kind 
as  takes  place  in  the  blast-furnace  itself  in  the  making 
of  iron  from  its  ore.  When  air  is  supplied  to  a  fire 
of  coke,  charcoal,  or  anthracite  coal,  it  is  believed  that 
one  particle  of  carbon  will  combine  with  two  particles 
of  oxygen  of  the  air,  the  nitrogen  being  carried  along 
as  inactive  and  neutral,  so  that  the  resulting  gas,  called 
carbon  dioxide,  or  CO2,  and  which  is  incombustible, 
is  called  the  product  of  complete  combustion  of  carbon 
and  oxygen.  If  this  particle  of  carbon  dioxide,  which 
is  one  particle  of  carbon  and  two  particles  of  oxygen 
combined,  be  passed  through  more  hot  coke  or  carbon, 
then  a  further  reaction  is  believed  to  take  place.  An- 
other particle  of  carbon  will  be  taken  up,  making  two 
particles  of  carbon  monoxide,  which  gas  consists  of 
one  particle  of  carbon  combined  with  one  particle  of 
oxygen,  and  which  is  combustible  because  it  is  capable 
of  taking  another  particle  of  oxygen  if  it  is  available. 
To  carry  out  this  double  chemical  reaction,  air  is  sup- 
plied to  a  very  thick  bed  of  fuel,  from  3  to  8  feet  thick, 
and  there  is  produced  a  combustible  gas.  All  the  coke 
or  fixed  carbon  is  consumed  or  converted  into  combus- 
tible carbon  monoxide  gas.  This  is  the  basal  principle 
for  the  gasifying  of  solid  carbon.  It,  together  with 
the  roasting  process,  constitutes  the  means  for  adapting 
coal  fuel  to  gas-engine  service,  or  the  means,  in  other 
words,  of  changing  any  kind  of  coal  completely  into 
combustible  gas  with  no  residue  and  no  by-products. 
The  apparatus  in  which  these  double  processes  are 
carried  out  is  called  a  gas  producer,  and  by  the  invention 
of  gas  producers  solid  fuels  became  available  for  gas- 


ADAPTATION  OF  FUELS 


185 


engines.  However,  differences  in  fuels  and  differences 
in  the  desired  kind  of  gas  have  led  to  very  great  differ- 
ences in  the  forms  of  gas  producers.  A  simple  gas 
producer  is  shown  in  Fig.  147.  It  is  a  chimney-like 
structure,  not  very  high  compared  with  chimneys, 
containing  a  grate  at  the 
bottom  through  which  air 
is  blown,  ashes  on  the  grate, 
coal  fed  from  the  top,  and 
the  various  steps  in  the  pro- 
cess of  gasification  indicated 
by  lines  drawn  across,  mak- 
ing zones  in  the  fire.  In  the 
first  zone  above  the  ashes 
the  temperature  is  highest, 
this  being  the  place  where 
carbon  is  completely  burned 
into  carbon  dioxide.  The 
next  zone  above  being 
less  hot,  the  carbon  dioxide 
is  here  reduced  to  carbon 
monoxide  ;  the  top  zone 
is  the  roasting  or  distilla- 
tion zone,  through  which  all 
the  gases  pass,  and  where 
the  gases  made  in  the  lower  zones  mix  with  those  dis- 
tilled from  fresh  coal  in  the  top,  the  whole  gas  mixture 
passing  over  through  pipes  preparatory  to  being  sup- 
plied to  engines.  Just  as  hydrogen  in  burning  com- 
bines with  oxygen  to  form  water  vapor,  so  will  water 
vapor  when  brought  into  heated  chambers  decompose 
into  hydrogen  and  oxygen;  and,  similarly,  when  brought 


FIG.  147 


186 


POWER 


into  contact  with  hot  carbon  the  oxygen  that  comes 
from  the  decomposition  of  the  water  combines  with 
the  carbon,  leaving  the  hydrogen  free.  If  water  vapor 
be  supplied  with  the  air,  the  gas  produced  in  such  a 
producer  will,  therefore,  consist  first  of  the  hydrocarbon 
products  of  distillation  or  roasting;  second,  of  carbon 
monoxide,  the  result  of  combination  of  fixed  carbon  with 
oxygen;  third,  of  hydrogen,  the  result  of  decom- 
position of  water  vapor  or  moisture  carried  in  the  air, 
or  of  steam  supplied  with  the  air;  fourth,  of  nitrogen 
carried  in  with  the  oxygen ;  fifth,  of  various  other  things 
in  quite  small  quantities,  such  as  some  free  oxygen  that 
has  escaped,  some  carbon  dioxide  that  failed  to  reduce, 
or  some  sulphurous  gases. 

If  such  a  producer  is  supplied  with  air  by  a  fan  or 
blower,  there  will  be  a  tendency  for  the  lower  part  to 

get  very  hot,  hot  enough 
to  melt  or  flux  the  ash 
and  make  clinker,  stop- 
ping up  the  air  supply. 
The  most  effective  way 
known  of  meeting  this 
trouble  is  to  supply 
steam  with  the  air.  As 
hydrogen  and  oxygen  in 
combining  liberate  heat,  so  will  the  water  vapor  on  de- 
composition absorb  heat,  and  steam  supplied  to  the  fire 
will  in  decomposing  in  the  hot  part  cool  it  sufficiently 
to  prevent  the  formation  of  clinker.  Continuous  opera- 
tion with  coals  that  tend  to  clinker  demands  means 
for  clinker  prevention,  and  this  led  to  the  application 
of  a  steam-jet  blower,  such  as  is  shown  in  Fig.  148, 


FIG.  148 


ADAPTATION   OF  FUELS 


187 


in  which  the  steam-jet  drives  along  the  air.  This 
blower  not  only  supplies  the  steam  necessary  to  pre- 
vent clinker,  but  the  air  for  combustion  with  the  coal. 
All  the  earlier  producers  used  to  drive  gas-engines  were 
operated  with  these  steam- jet  blowers.  One  of  these 
producers,  of  American  design, 
very  largely  used,  is  shown  in 
Fig.  149,  in  which,  however, 
the  blower  is  omitted.  It 
would  be  attached  to  the 
blast-pipe  at  the  left.  The 
end  of  the  blast-pipe  has  a 
cap  which  serves  to  throw  the 
air  and  steam  mixture  more 
or  less  uniformly  across  the 
whole  bed  and  to  keep  ashes 
out  of  the  pipe.  On  the 
grates,  which  are  inclosed  in 
a  tight  chamber  to  prevent 
the  escape  of  the  blast,  a 
considerable  amount  of  ash 
is  left  at  all  times  to  avoid 
burning  them.  A  crank  out- 
side enables  the  shaking  down 
of  ash  to  maintain  a  proper  level  without  opening  the 
ash  chamber,  but  once  a  day  this  is  opened  to  remove 
collected  ash.  Another  style  of  the  same  producer 
without  any  grates  is  shown  in  Fig.  150.  Here  the 
ashes  simply  rest  in  a  water  trough  at  the  bottom,  and 
the  edge  of  the  casing  dips  into  the  water  far  enough 
to  prevent  escape  of  air  from  the  interior.  Ashes  may 
be  removed  from  this  water-seal  bottom  by  raking 


FIG.  149 


188 


POWER 


under  the  water  at  any  time.  Producers  such  as  have 
just  been  shown,  operated  with  the  draft  upward  and 
under  pressure,  are  called  up-draft  pressure  producers. 
These  had  not  been  in  use  for  many  years  in  Germany, 
where  they  had  their  most  vigorous  development, 
before  it  was  realized  that  the  suction  stroke  of  the 
engine  in  drawing  in  its  charge  of  air  and  gas  might  be 

made  to  also  draw 
the  air  and  steam 
through  the  coal- 
bed  of  the  produ- 
cer. This  seemed 
especially  desirable 
because  the  steam- 
jet  blower  type  of 
producer  required 
the  addition  of  a 
steam-boiler  to  pro- 
duce the  high- 
pressure  steam  re- 
quired, and,  more- 
over, considerable 
variation  in  the  proportion  of  air  to  steam,  with  conse- 
quent variable  quality  of  gas,  could  not  be  avoided. 
This  boiler,  if  the  blast  were  to  be  produced  by  the 
engine  suction  alone,  would  not  be  necessary,  nor  would 
a  separate  engine-driven  blower  be  necessary  as  a  sub- 
stitute for  the  jet  blower.  The  new  combination  became 
known  as  the  suction  gas  producer,  one  style  of  which 
is  shown  in  Fig.  151  in  section  and  externally  in 
Fig.  152.  The  gas  on  leaving  the  producer  proper  is 
shown  at  the  left  passing  through  a  chamber  fitted 


FIG.  150 


ADAPTATION   OF   FUELS 


189 


with  tubes  which  are  surrounded  by  water.     The  gases 
leaving  the  producer  warm  this  water,  producing  water 


FIG.   151 


vapor  or  steam,  which  is  drawn  into  the  bottom  of  the 
producer  with  the  air  through  a  connection  not  shown. 
The  hot  gases  from  the  producer  make  all  the  steam 


FIG.  152 


190 


POWER 


necessary  to  prevent  clinkering  and  without  any  high- 
pressure  boiler.  After  leaving  this  vaporizer  the  hot 
gases  pass  through  a  tower  chamber  full  of  coke  or  any 
other  similar  porous  substance  kept  continuously  wet 
by  a  water  spray  at  the  top.  This  serves  the  double 
purpose  of  cooling  the  gas  and  removing  from  it  most 
of  its  coarser  particles  of  dust  carried  from  the  fire. 
Finer  particles  of  dust,  together  with  particles  of  tar 
which  may  have  come  from  the  roasting  of  the  green 


FIG.  153 

coal,  are  removed  later  by  passing  the  gas  through 
layers  of  sawdust  and  wood  shavings  in  a  sort  of  tar 
extractor  or  purifier.  From  this  last  cleanser  the  gas 
passes  directly  to  the  engine,  the  entire  flow  through 
the  apparatus  being  caused  by  the  suction  of  the  engine 
itself.  A  slightly  different  design  of  the  same  type 
of  producer  is  shown,  together  with  the  engine,  in  Fig. 
153.  With  a  view  to  simplification,  some  of  these 
suction  producers  are  arranged  with  the  vaporizer 
around  the  top  of  the  producer  chamber  itself,  thus 
making  a  separate  vaporizer  chamber  unnecessary. 


ADAPTATION   OF  FUELS 


191 


Such  a  producer  as  this  is  shown  in  Fig.  154  without 
any  of  the  additional  parts.  The  air  is  drawn  over  the 
top  of  the  warm  water  before  entering  the  ash-pit,  and  a 
float-valve  chamber  is  provided  to  keep  the  water- 
level  constant.  A 
small  blower  is  pro- 
vided at  the  bottom 
to  supply  the  air. 
With  a  view  to  ad- 
justing the  quantity 
of  steam  to  the  air 
a  little  more  posi- 
tively, special  de- 
vices have  been 
designed,  in  which 
water  is  fed  to  a 
pipe  dipping  into 
the  hot  discharge 
gases  so  that  it  is 
warmed  almost  to 
the  boiling  point,  FlG.  154 

It  then  drops  into 

a  funnel  that  guides  it  to  a  narrow  cast-iron  trough 
running  around  the  producer  top  casting  and  which  is 
hot  enough  to  vaporize  all  such  water  before  it  gets  to 
the  end.  Air  drawn  into  a  hot  gas  heater  and  warmed 
by  ribs  passes  over  to  the  vaporizer  casting,  so  that 
the  steam  there  formed  mixes  with  it.  By  this  means 
the  mixture  proportions  of  air  to  steam  can  be  con- 
trolled at  will.  If  nothing  but  air  be  supplied  to 
these  producers,  there  will  be  no  hydrogen  in  the  gas. 
If  nothing  but  steam  be  supplied,  and,  of  course,  this 


192  POWER 

is  only  possible  for  a  short  time,  as  it  will  put  out  a 
fire  if  continued  too  long,  there  will  be  a  great  deal  of 
hydrogen.  Therefore,  as  the  quality  of  the  gas  varies 
quite  rapidly  with  the  amount  of  hydrogen  it  contains, 
the  quality  will  in  turn  vary  every  time  the  proportion 
of  steam  to  air  supplied  is  varied.  Steam- jet  blowers 
are  unable  to  maintain  this  proportion  correctly. 
Separate  vaporizers  on  suction  producers,  or  other 
contained  vaporizers  on  the  producer  bed,  are  better, 
but  still  not  quite  satisfactory,  so  there  has  been  made 
a  series  of  attempts  to  maintain  this  proportion  constant 
automatically  by  mechanical  means.  These  are  so 
numerous  and  so  different  that  it  would  be  quite  im- 
possible to  examine  them,  but  it  should  be  noted  that 
this  is  a  very  important  matter  and  one  now  receiving 
a  good  deal  of  attention.  Another  matter  receiving 
attention  at  this  time  is  the  means  of  keeping  the  bed 
compact,  for  if  the  bed  should  not  be  compact  and  holes 
should  form  in  it,  the  chemical  processes  that  should 
be  carried  out  will  not  take  place,  and  there  will  result 
a  considerable  loss  of  efficiency  and  bad  or  unsteady 
gas  will  be  produced. 

All  of  these  producers  shown  work  quite  well  with 
coke  or  anthracite  coal  in  spite  of  tendencies  to  make 
variable  gas,  if  skilfully  operated,  but  most  of  them 
work  quite  badly  with  bituminous  coal  because  of  the 
coking  and  tar  tendencies.  Bituminous  coal  may  or 
may  not  cake,  but  always  contains  much  tar.  This 
tar,  if  it  lodges  on  the  engine  valves  or  moving  parts, 
will  make  them  stick ;  if  it  gets  into  the  interior  of  the 
cylinder,  it  will  make  deposits  of  carbon  which  are  very 
bad  on  the  action  of  the  engine.  The  tar  must,  there- 


ADAPTATION  OF  FUELS  193 

fore,  be  eliminated  or  means  be  provided  for  preventing 
it  reaching  the  engine.  Naturally,  the  first  idea  to 
be  applied  was  that  of  removal  after  formation.  Tar 
was  allowed  to  form  in  the  producer  and  extractors 
were  made  to  get  it  out  of  the  gas.  The  means  first 
employed  were  very  similar  to  those  adopted  for  re- 
moving the  dust  from  gas,  which  means  are  most  elab- 
orately carried  out  and  applied  to  the  gas  from  blast 
furnaces,  as  it  is  most  dirty. 

There  are  a  great  many  processes  and  apparatus  avail- 
able for  removing  dirt  more  or  less  completely,  most  of 
them  quite  simple  in  idea.  One  of  the  most  common  is 
the  spray  tower  already  referred  to,  n  which  the  gas 
enters  the  bottom,  passing  upward  through  wet  coke,  over 
which  water  is  sprayed  from  the  top  and  runs  downward  to 
keep  the  coke  wet.  The  primary  object  of  this  sort  of 
cleaning  tower  is  to  catch  dust,  and  this  it  does  pretty  well. 
It  also,  however, .  cools  the  gas  and  so  causes  a  certain 
amount  of  tar  vapor  to  condense  in  small,  liquid  tar 
drops  which  the  coke  is  ineffective  in  removing.  Other 
forms  of  tower  involve  all  sorts  of  systems  for  extend- 
ing to  the  gas  a  great  number  of  square  feet  of  wet  sur- 
face by  allowing  the  water  to  fall  over  piles  of  wood  or 
through  series  of  metal  bars  or  over  plates.  All  cleaners 
of  this  class  may  be  called  static  cleaners  of  the  contact 
sort.  By  narrowing  the  spaces  through  which  the  gas 
must  pass,  especially  when  the  substance  is  absorbent, 
there  results  the  filter  type  of  cleaner.  In  this  the  gas 
is  forced  through  spaces  between  finely  divided  material 
such  as  sawdust,  cheese-cloth,  excelsior,  or  wood-chips. 
Such  a  cleaner  is  shown  in  Fig.  155,  in  which  the  fibrous 
or  filter  material  rests  on  pans,  arranged  for  convenient 


194 


POWER 


removal  when  dirty.     As  tar  is  greasy  and  most  of  the 

static  cleaners  and  filters  get  wet,  they  soon  cease  to 

absorb,  as  the  water  repels  the  oily  tar.  A  third  class 

of  cleaner,  which  has 
proved  more  effective 
for  tarry  substances, 
but  which  is  also  effec- 
tive for  dust,  is  me- 
chanical in  action. 
Rotating  blades  dip- 
ping into  water  throw 
a  continuous  spray 
across  the  chamber 
through  which  the  gas 
must  pass,  at  the  same 

time  exerting  a  churning  action  to  concentrate  the  tar 

drops,  much  the  same  as  a  butter  churn  collects  particles 

of  butter  fat.     Such  a  cleaner  is  shown  in  Fig.  156. 

The  ribs  on  the  drum  D  , 

catch  up  water  in  the 

bottom    of    the  casing 

and   throw   it    out    by 

centrifugal    force,    the 

gas  meanwhile  passing 

through    the    veils    of 

mist    at    right    angles 

and  suffering  a  beating 

by    the    ribs    and    the 

heavy  drops  of  water.  FIG  156 

These  few  examples  will 

serve  to  show  the  typical  means  employed  to  solve  this 

most  important  part  of  the  problem  of  the  preparation 


ADAPTATION   OF  FUELS  195 

of  gas,  made  from  bituminous  coal  and  containing  tar, 
for  engine  use.  Tar  extractors  have  been  based  on 
practically  every  plan  ever  proposed  for  dust  removal ; 
the  passing  of  the  gases  over  wet  surfaces,  which  did 
not  work  very  well  because  tar  is  greasy  and  slips  past ; 
the  filtering  method  likewise;  and  finally  all  sorts  of 
elaborate  churns,  and  these  churns  are  now  the  main 
dependence. 

Even  if  separation  is  complete,  an  additional  diffi- 
culty in  operation  is  encountered  in  bituminous  pro- 
ducers, in  which  the  volatile  gases  are  allowed  to  mix 
with  the  gasified  coke,  as  is  done  in  all  these  systems 
that  depend  on  tar  removal  later,  and  this  is  the  fluc- 
tuation in  the  quality  of  the  gas.  The  volatile  gases 
driven  off  in  roasting  have  about  six  times  the  heating 
power  of  the  gasified  coke,  so  that  any  change  in  the 
proportion  of  these  gases  makes  a  considerable  change 
in  the  quality  of  the  final  gas  mixture. 

Belief  is  growing  at  the  present  time  that  it  is  not 
sufficient  merely  to  attach  to  bituminous  producers 
tar  extractors,  nor  advisable  even  though  it  were  suffi- 
cient, as  the  primary  trouble  is  in  the  fire  itself,  and 
means  are  being  sought  for  changing  conditions  in  the 
fire  so  that  the  tar  will  not  be  formed  at  all,  or  if  formed, 
be  destroyed.  Various  plans  have  been  tried  and 
others  are  being  proposed  every  day  ;  some  of  them  are 
in  the  experimental  stage,  others  no  more  than  pro- 
posals for  overcoming  the  difficulties  of  caking,  tar 
formation,  and  the  fluctuating  amounts  of  volatiles 
from  the  rich,  bituminous  coals.  One  principle  for 
the  destruction  of  the  tar  involves  the  reversal  of  the 
draft,  so  that  coal  fed  to  the  top  would  be  supplied  with 


196  POWER 

air  at  the  same  point  which  would  pass  downward 
through  the  bed  instead  of  upward.  The  passage  of 
the  volatiles  of  the  coal  downward  through  the  bed  is 
expected  to  decompose  the  tarry  hydrocarbons,  break- 
ing them  up  into  permanent  gases  and  fixed  carbon 
soot  that  is  more  easily  filtered  out  than  greasy  tar, 
and  this  plan  is  fairly  effective.  One  example  of  this 
system  is  illustrated  in  section  in  Fig.  157,  in  which 
there  are  two  gas  generators  used  alternately.  Air 
is  drawn  through  the  bed  downward  by  a  suction 


FIG.  157 

blower  shown  about  the  center  of  the  picture.  The 
hot  gases  first  pass  through  a  tubed  steam-boiler  and 
then  are  cooled  in  a  wet  tower.  After  cooling,  the  gas 
passes  through  a  blower  to  a  soot  filter  and  finally  to  a 
gas-holder.  This  operation  makes  the  bed  very  hot ; 
when  it  gets  as  hot  as  is  permissible  the  air  is  shut  off 
and  switched  to  the  other  producer,  and  steam  from 
the  boiler  is  blown  through  the  first,  making  a  gas  rich 
in  hydrogen,  until  the  bed  has  cooled.  The  alternately 
made  rich  and  poor  gases  are  mixed  to  get  a  uniform 
gas  for  the  engine. 

In  this  system  practically  all  tar  is  destroyed,  but 


ADAPTATION   OF  FUELS 


197 


soot  is  found  instead.  A  producer,  based  on  a  com- 
bination of  up-and-down  draft  and  continuously  operat- 
ing, is  shown  in  Fig.  158,  together  with  the  cleaner  and 
suction  blower.  Coal  fed  at  the  top  passes  downward 
and  some  air  with  it,  the  volatiles  perhaps  partly  de- 
composing. Air  also  passes  upward  from  the  water- 
sealed  bottom  and  the  gases  formed  in  both  the  upper 


FIG.  158 

and  lower  chambers  mix  and  pass  out  at  the  middle. 
Around  this  central  zone  is  placed  a  ring  trough  con- 
taining water,  over  which  all  entering  air  passes  and 
takes  up  steam  enough  to  keep  the  bed  cool. 

By  this  plan  there  might  be  expected  both  tar  and 
soot  in  proportion,  depending  on  the  adjustment  of 
top  and  bottom  blast  and  bed  temperature,  such  vola- 
tiles as  are  only  slightly  heated  yielding  tar,  the  rest 
that  are  highly  heated  yielding  soot.  Should  the  coal 
cake  much  while  roasting,  both  these  producers  would 


198 


POWER 


require  much  poking  to  prevent  the  stoppage  of  air. 
A  still  more  radical  plan,  toward  which  the  latest 
thought  seems  to  be  directed,  involves  the  elimination, 
not  only  of  all  the  tar  and  soot,  but  also  all  the  rich 
volatiles  of  the  coal,  making  a  larger  amount  of  weak 
gas  but  very  constant  in  quality.  The  basal  idea  un- 
derlying the  accomplishment  of  this  object  is  well  illus- 
trated by  a  combina- 
tion of  the  beehive 
oven  and  the  blast 
furnace.  The  bee- 
hive oven  roasts  the 
coal,  burns  up  the 
volatile,  and  makes 
coke;  the  blast  fur- 
nace completely  gasi- 
fies this  coke 
and  is  capable 
also  of  causing  a 
combustion  be- 
tween its  coke 
and  the  waste 
gases  of  the  bee- 
hive. If,  then,  the  top  of  the  beehive  oven  be  con- 
nected to  a  blast-furnace  air  supply,  the  products  of 
combustion  of  the  volatile  from  the  oven  can  be  made 
to  combine  with  the  coke  of  the  furnace  and  the  supply  of 
coke  will  likewise  be  maintained  by  the  oven.  In  Fig.  159 
one  form  of  producer  embodying  this  idea  is  shown. 
There  are  two  parts  to  the  fuel  bed,  the  first  or  upper  part 
resting  on  a  grate  /,  through  which  the  air  can  pass, 
burning  some  of  the  coal  just  as  it  burns  under  a  boiler, 


FIG.  159 


ADAPTATION  OF  FUELS  199 

but  roasting  out  the  volatiles.  As  the  coal  passes  down 
and  across  the  grate,  all  the  tarry  substances  may  be 
driven  off  and  in  burning  fill  the  upper  chamber  with 
a  long  flame.  At  the  bottom  of  this  grate  most  of  the 
volatiles  will  have  roasted  out  and  burned  as  in  the 
beehive  oven,  leaving  coke  for  the  lower  chamber. 
Through  this  main  coke  bed  the  burnt  products  of 
the  volatiles  will  pass  and  be  reduced  to  combustible 
carbon  monoxide  gas  and  hydrogen  by  chemical  com- 
bination with  the  coke.  No  producer  of  this  class  is  yet 
in  use,  and  this  one  is  shown  merely  to  illustrate  another 
idea  for  meeting  the  difficulties  of  securing  a  suitable 
gas  for  engines  from  bituminous  coal.  That  there  are 
real  difficulties  in  the  complete  gasification  of  bitumi- 
nous coals  and  other  special  grades  of  coal,  such  as 
peat,  was  not  originally  realized;  but  now,  as  the  prob- 
lem is  more  completely  understood,  great  progress  is 
being  made,  so  that  before  long  it  will  be  possible  to 
gasify  every  grade  of  fuel  as  well  as  can  now  be  done 
with  anthracite  and  coke.  When  this  happens,  the  gas- 
power  plant  will  become  a  universal  competitor  of  the 
steam-power  plant  so  far  as  the  fuel  supply  is  concerned, 
and  in  competition  with  steam  will  make  it  possible 
to  secure  more  power  from  coal  than  we  now  get. 
In  plants  of  large  size  20  per  cent  excess  efficiency 
over  steam  may  now  be  secured,  while  in  small  ones  of 
about  100  h.  p.,  the  steam  plant  will  burn  four  or  five 
times  as  much  coal  per  horse-power  hour  as  the  gas 
plant  consisting  of  producers  and  gas-engines.  This 
is  especially  interesting  and  important  when  it  is  re- 
membered that  the  average  power  plant  is  small,  - 
less  than  100  h.  p.  in  the  manufacturing  industries, 


200  POWER 

according  to  the  last  census,  —  so  that  for  the  country 
as  a  whole,  it  is  of  far  more  importance  to  improve 
fuel  consumption  in  small  plants  than  in  those  great 
ones  familiar  to  New  York,  used  for  the  trolley  roads 
and  central  stations.  The  gas  producer  and  gas-engine 
may,  therefore,  be  regarded  as  important  factors  in 
the  future  of  power  development  and  most  effective  in 
saving  coal  in  those  plants  which  represent  the  average 
power 'requirements  of  individual  users. 

What  these  small  producer  gas  plants  are  doing  for 
the  average  power  user  with  solid  fuels,  the  oil  or 
gasolene  engine  is  doing  in  even  greater  degree  for  other 
fields  that  it  has  made  especially  its  own,  and  in  which 
it  has  in  some  cases  absolutely  no  rivals.  Liquid  oil 
fuel  as  obtained  naturally  is  a  mixture  of  many  things, 
and  when  heated  in  retorts  or  stills  will  yield  those 
substances  in  a  certain  order.  Substances  like  gasolene 
begin  to  boil  out  first,  are  condensed,  and  sold  under  a 
trade  name.  As  the  temperature  rises  in  the  retort  or 
boiler,  when  the  gasolene  is  nearly  gone,  a  heavier  sub- 
stance is  obtained  called  kerosene ;  after  this  has  all 
passed  over,  the  residue  may  be  sold  as  fuel  oil,  or  from 
it  lubricating  oil,  vaseline,  paraffine,  or  asphalt  may 
be  obtained.  Thus,  a  great  variety  of  substances  may 
be  obtained  from  natural  oils,  differing,  so  far  as  their 
use  in  engines  is  concerned,  chiefly  in  the  temperature 
to  which  they  must  be  heated  to  vaporize  them.  In 
any  case  overheating  will  produce  the  same  effects  as 
the  heating  of  the  volatiles  from  coal ;  it  will  cause 
decomposition  into  other  lighter  vapors  or  fixed  gases 
and  soot. 

Another   sort   of   liquid   fuel   has   recently   become 


ADAPTATION  OF  FUELS  201 

available  in  this  country,  known  as  denatured  alcohol, 
and  sometimes  sold  under  trade  names,  such  as  Pyro. 
This  is  made  in  much  the  same  way  as  is  whisky, 
by  fermentation  and  distillation  of  any  substances 
containing  starch  or  sugar,  the  substances  most  com- 
monly used  being  corn  and  potatoes.  This  alcohol 
is  very  useful  for  engines,  vaporizing  more  easily  than 
kerosene,  but  not  so  easily  as  gasolene.  It  is  nearly 
pure  alcohol,  to  which  is  added,  to  prevent  evasion  of 
the  liquor  tax,  substances  like  wood  alcohol  and  ben- 
zine in  small  quantities  which  do  not  affect  its  fuel 
value. 

Liquid  fuels  are  adapted  to  engine  use  in  two  char- 
acteristic ways,  one  direct  and  the  other  indirect.  The 
indirect  method  is  used  with  all  fuels  easily  vaporized, 
while  the  direct  system  is  used  for  the  heavy  oils  diffi- 
cult to  vaporize.  With  the  lighter  and  more  volatile 
fuels  a  mixture  is  made  external  to  and  independent 
of  the  engine  by  apparatus  corresponding  to  the  mixing 
valve  of  gas-engines,  whereas  the  heavy  oils  are  most 
often  injected  directly  into  the  explosion  chamber. 
The  more  volatile  forms  of  fuels  are  treated  by  devices 
termed  carbureters,  which  perform  a  variety  of  func- 
tions at  once:  they  automatically  control  the  feed  of 
the  fuel,  vaporize  it,  mix  it  with  the  air,  and  maintain 
the  correct  proportions  of  vapor  to  air.  Thus,  in  Fig. 
160,  if  gasolene  is  supplied  to  a  float  chamber  through 
the  little  valve  in  the  top,  controlled  by  the  float,  the 
supply  will  be  shut  off  when  the  float  in  the  chamber 
reaches  a  certain  height  and  opened  if  the  level  falls 
below  this  point.  If,  now,  there  be  a  nozzle  connected 
with  the  gasolene  from  the  constant  level  float  chamber, 


202 


POWER 


the  end  of  the  nozzle  just  a  little  above  the  level  in 
the  float  chamber,  and  there  be  a  needle  valve  in  the 
nozzle  to  adjust  the  effective  opening,  no  gasolene  will 
flow  out  except  when  the  movement  of  the  piston  creates 
a  suction  at  the  nozzle,  and  the  amount  that  will  flow 
under  suction  will  depend  on  the  amount  of  suction 
and  the  needle  valve  adjustment.  To  facilitate  ad- 


FIG.  160 

justment  of  the  suction  in  the  nozzle  chamber  a  valve 
may  be  provided  in  the  air-pipe,  as  shown  at  the 
right,  and  the  proportions  between  the  gasolene  and 
the  air  be  maintained  by  the  needle  valve  and  the 
air-valve,  just  about  the  same  as  was  done  with  the 
mixing  valves  for  the  gas-engines  previously  described. 
It  is  found  by  experience  that  there  is  a  tendency  for 
the  gasolene  to  increase  faster  than  the  air  when  the 


ADAPTATION  OF  FUELS 


203 


suction  increases,  and  for  that  reason  an  auxiliary  air 
valve  is  often  provided,  either  hand  adjusted  or  auto- 
matic. Such  a  combination  of  parts  constitutes  a 
carbureter.  Vaporizing  in  it  is  quite  automatic,  as 
the  air  is  hot  enough  to  vaporize  the  gasolene  spray 
by  contact  alone,  or  vaporize  enough  of  it  to  permit  the 
cylinder  to  complete  the  process  in  compression.  In 


FIG.  161 


place  of  the  float  chamber  there  may  be  a  pump-sup- 
plied cup  with  an  open  overflow,  as  shown  below,  to 
keep  the  level  constant.  It  would  be  easy  to  show 
perhaps  300  different  combinations  of  mechanisms  all 
constituting  carbureters,  operating  on  about  the  same 
ideas,  but  the  standard  adopted  principle  is  well  in- 
dicated by  this  diagram.  In  Fig.  161  is  shown  a  car- 
bureter from  an  automobile  engine,  as  an  example  of 
one  actual  form  in  which  the  air  may  enter  through 
two  passages,  one  the  spray  chamber  B,  and  the  other 
ports  C.  These  ports  constitute  the  auxiliary  air  inlet 
previously  mentioned,  and  the  adjustment  of  propor- 
tions is  accomplished  by  the  needle  valve. 


204  POWER 

Carbureters  operating  on  these  principles  and  using 
gasolene  fuel,  to  which  they  are  adapted,  made  the 
light-weight  self-contained  engine  a  possibility,  and  were 
fundamental  to  the  creation  of  the  automobile,  motor 
boat,  and  the  aeroplane.  They  also  supplied  means 
for  providing  the  small  power  user,  like  the  farmer  or 
operator  of  the  small  isolated  country  shop,  with  a 
machine  to  do  the  work  formerly  done  by  man  or 
horses. 

For  farm,  country  residence,  and  small  shop  use, 
there  are  sold  in  this  country  yearly  close  to  100,000 
of  these  small  gasolene  engines  for  application  where 
practically  no  other  source  of  power  would  be  avail- 
able. Over  280,000  automobiles  are  built  annually, 
approximating  in  value  $400,000,000,  and  giving  em- 
ployment in  more  than  200  factories  to  120,000 
workmen,  not  counting  those  who  are  also  given 
employment  in  running  these  machines  and  keep- 
ing them  in  repair  after  they  are  sold.  The  engines 
of  these  automobiles  aggregate  80,000  h.  p.,  and 
their  value  is  equal  to  that  of  17,000  consolidation 
locomotives,  which  is  about  three  times  the  yearly 
demand  on  the  railroads,  so  that  the  value  of  the  auto- 
mobile output  is  in  a  fair  way  to  exceed  that  of  all  the 
locomotive  construction  in  this  country.  The  small 
gasolene  engine  has  produced  industrial  effects  of  enor- 
mous magnitude,  out  of  all  proportion  to  the  machine 
itself.  The  little  engine  that  is  responsible  for  such 
a  far-reaching  influence  is  decidedly  insignificant  in 
comparison  with  the  big  central  station  and  steamship 
engine.  In  its  own  field  this  little  engine  has  no  rivals, 
and  this  is  especially  significant,  for  it  must  be  re- 


ADAPTATION  OF  FUELS  205 

membered  that  without  it  hundreds  of  thousands  of 
men  would  be  doing  work  by  hand,  or  with  horses,  in 
shops  and  on  farms,  that  is  now  done  by  power,  and 
which  steam  is  absolutely  incapable  of  doing,  or  that 
work  would  remain  undone.  As  a  matter  of  fact  there 
is  no  known  system  of  power  capable  of  doing  these 
same  things,  except  possibly  the  same  engine  adapted 
to  use  the  other  liquid  fuels  such  as  kerosene,  alcohol, 
or  the  residue  of  crude  oil  distillation. 

These  other  fuels,  however,  are  not  so  easily  adapted 
to  the  use  of  the  engine  as  gasolene  because  of  the  greater 
difficulty  of  vaporizing  them.  They  must  all  be  pro- 
vided with  a  source  of  heat,  which  the  gasolene  does 
not  need.  By  feeding  alcohol  or  kerosene  to  such  a 
carbureter  as  has  been  described,  there  will  be  formed 
a  spray,  but  before  an  explosive  mixture  can  be  pro- 
duced and  introduced  into  the  cylinder,  some  heat 
must  be  applied.  This  heat  is  applied  in  a  variety  of 
ways.  Perhaps  the  simplest  to  understand  is  that  in 
which  the  sprayed  air  mixture  is  led  through  iron 
chambers  on  its  way  to  the  engine,  which  chambers 
are  heated  first  by  a  lamp  and  later  by  the  exhaust 
gases  after  the  engine  begins  to  operate.  In  other 
devices  the  heated  part  is  internal  to  the  engine,  and 
the  spray  obtained  from  the  carbureter  is  introduced 
into  the  cylinder,  there  to  be  heated  by  contact  with 
hot  iron  parts  which  were  warmed  by  the  last  explosion. 
When  these  parts  that  are  to  heat  the  spray  and  vapor- 
ize it  are  internal,  then  the  engine  must  be  started  on 
gasolene  or  some  equally  volatile  substance,  such  per- 
haps as  ether.  Another  plan  involves  the  use  of  a 
heater  for  the  oil  alone  with  a  view  to  converting  it 


206  POWER 

into  a  gas  or  vapor.  According  to  this  plan  the  oil  is 
fed  to  hot  chambers,  by  the  heat  of  which  some  of  it  is 
converted  into  a  reasonably  fixed  gas,  while  the  rest 
is  decomposed  into  a  sooty  residue.  This  fixed  gas  can 
then  be  supplied  to  the  engine  as  would  any  other  gas. 
Still  another  plan,  which  is  confined  to  the  use  of  dis- 
tillates, involves  the  feeding  of  the  fuel  to  a  little  boiler 
where  it  is  vaporized  by  a  lamp  or  exhaust  gases.  The 
vapor  thus  produced  is  mixed  with  air  as  a  gas  would 
be.  Of  course,  all  these  devices  have  limitations. 
When  vapor  is  formed  in  boilers,  means  must  be  adopted 
to  prevent  its  subsequent  condensation  and  to  regulate 
the  amount  produced.  When  the  oil  is  dropped  on 
to  hot  plates,  means  must  be  provided  to  prevent  them 
getting  too  hot,  otherwise  the  decomposition  and  soot 
formation  will  be  excessive.  When  the  oil  is  heated 
by  itself,  the  device  is  generally  termed  a  separate 
vaporizer,  which  must  be  used  in  connection  with  a 
mixing  valve  similar  to  those  used  on  gas  engines  to 
adjust  the  proportions  of  vapor  to  air  as  required  by 
the  engine.  When,  however,  a  spray  is  formed  and 
that  spray  is  subsequently  heated,  then  the  device  is 
called  a  carbureting  vaporizer  or  just  a  carbureter, 
or  sometimes  just  a  vaporizer.  Practice  in  this  regard 
is  not  yet  standardized. 

For  very  heavy  oils,  such  as  the  residue  oils,  a  differ- 
ent plan  has  been  adopted.  The  oil  is  injected  directly 
into  the  combustion  chamber,  generally  by  means  of  a 
pump.  The  chamber  into  which  the  oil  is  thus  sup- 
plied is  hot,  the  heat  being  obtained  in  some  cases  en- 
tirely by  compressing  air  alone,  and  in  other  cases 
entirely  by  metal  parts  such  as  plates  and  bulbs,  and 


ADAPTATION  OF  FUELS 


207 


in  still  others  by  a  combination  of  these  two.  One  of 
the  most  famous  heavy  oil  engines,  and  one  that  holds 
the  record  for  thermal  efficiency,  approaching  almost  40 
per  cent  on  test  and  averaging  over  30  per  cent  in  daily 
use,  draws  in  a  charge  of  air  in  the  usual  gas-engine  way, 
compresses  it  to  between  500  and  600  pounds  per  square 
inch,  which  makes  the  air  about  red-hot.  Into  this 
red-hot  air  the  oil  is  squirted  by  a  pump  in  carefully 
regulated  amounts,  assisted  by  a  small  jet  of  compressed 
air  from  a  tank  under  about  1000  pounds  pressure. 
These  engines 
are  expensive 
to  build  and 
somewhat  diffi- 
cult to  main- 
tain, so  that 
the  other  de- 
vice of  using 
hot  plates  has 
been  more 
widely  used. 
One  of  the  most 

common  forms  of  these  hot  plates  is  the  bulb  form. 
Such  a  vaporizer  is  shown  in  Fig.  162,  forming  part 
of  an  ordinary  four-cycle  engine.  It  is  ordinary  in 
all  respects  except  one,  for  it  has  in  place  of  the 
regular  head  a  bulblike  chamber  connected  to  the 
cylinder  by  a  neck.  This  bulb  chamber  at  its  outer 
end  gets  red-hot  in  operation  and  in  the  beginning  is 
heated  by  a  lamp  placed  under  it.  Heavy  oil,  even  as 
thick  as  molasses,  when  pumped  into  this  chamber  will 
vaporize,  but  some  of  it  is  apt  to  decompose  by  over- 


FIG.  162 


208 


POWER 


heating.  The  compression  stroke  of  the  piston  will 
force  air  into  the  chamber  and  in  passing  the  neck  at 
high  speed  the  air  will  whirl  around  inside  the  bulb, 
mixing  with  the  vapor.  Ultimately,  as  the  compres- 
sion is  carried  on,  the  mixed  vapor  and  air  become 
heated  enough  to  cause  an  automatic  or  self-ignition, 
but  usually  not  until  the  whirling  stops,  about  the  end 
of  the  compression  stroke.  Another  form  of  this  hot 

bulb  vaporizer, 
which,  of  course, 
is  always  fed  by 
a  pump  of  vari- 
able capacity 
under  governor 
control,  is  shown 
in  Fig.  163  in 
connection  with 
a  two-cycle  en- 
gine. Here  a 
lamp  is  shown 
under  the  hot 

bulb  B,  which  has  a  lip  L  projecting  into  the  cylinder. 
The  pump  P  discharges  oil  from  the  tank  downward 
through  a  nozzle  on  to  the  lip,  lip  and  bulb  being  red- 
hot.  Compression  of  the  piston  forces  air  over  the  lip 
L  into  the  bulb  7,  carrying  all  vapor  and  unvaporized 
oil  with  it.  At  the  end  of  the  compression  stroke  all  the 
oil  is  vaporized,  and  the  mixture  warmed  up  enough  to 
be  ignited  by  the  red-hot  metal,  but  as  some  of  the  oil 
is  sure  to  be  overheated  before  it  burns,  a  little  residue 
will  form.  The  rest  of  the  operation  is  substantially 
the  same  as  that  for  a  two-cycle  gas-engine,  previously 


FIG.  163 


ADAPTATION   OF  FUELS  209 

described.  Still  another  and  more  recent  plan  for 
handling  these  very  heavy  oils  seeks  to  avoid  entirely 
a  dependence  on  the  vaporizer.  It  has  already  been 
pointed  out  that  a  fine  spray  of  oil  when  uniformly 
distributed  through  air  will  make  just  as  good  an 
explosive  mixture  as  the  vapor  and  air.  Of  course, 
the  spray  must  be  very  fine!  In  one  recent  type  of 
oil-engine  this  is  secured  by  pumping  the  oil  into  a 
little  cartridge  connecting  with  the  explosion  chamber 
by  a  small  valve.  This  cartridge  is  also  supplied  with 
highly  compressed  air,  and  at  the  time  when  an  ex- 
plosion is  wanted  the  connecting  valve  is  opened,  air 
and  oil  rushing  into  the  explosion  chamber  together; 
the  expanding  air  spatters  the  oil  into  a  very  fine  mist, 
blowing  it  more  or  less  uniformly  into  a  charge  of  warm 
compressed  air  that  has  been  prepared  by  the  engine 
piston  on  its  compression  stroke.  By  this  arrange- 
ment an  explosion  can  be  obtained  instantly,  even 
from  oil  that  is  very  sticky  and  thick,  the  combustion 
and  efficiency  being  quite  as  good  as  with  the  red-hot 
air  previously  noted,  and  without  using  over  a  third 
of  the  compression  the  latter  requires.  These  heavy 
oil  engines,  while  they  have  a  limited  field  of  application 
because  of  the  localized  and  limited  supply  of  oil,  do 
nevertheless  fill  a  most  useful  gap  in  the  power  field, 
for  in  many  places  the  fuel  oil  is  far  cheaper  than  coal, 
and  in  others,  such  as  California,  far  from  the  coal  fields, 
oil  is  comparatively  plentiful.  They  are  more  costly 
than  gasolene  engines  to  buy,  but  their  fuel  is  much 
cheaper,  and  as  they  are  not  so  readily  started  as  the 
gasolene  engine  they  divide  the  liquid  fuel  field. 

The  gas  producer  operating  on  solid  fuel,  the  light 


210  POWER 

oil  carbureter,  and  the  heavy  oil  vaporizer  constitute 
the  means  by  which  the  natural  fuels  have  been  and 
are  being  adapted  to  the  use  of  the  gas-engine,  the 
most  efficient  machine  for  deriving  power  from  the  heat 
of  combustion.  So  constantly  high  is  the  efficiency  of 
these  engines  for  all  types  and  sizes,  that,  in  spite  of 
higher  investment  costs,  they  offer  to  the  small  power 
user  means  of  generating  power  as  cheaply  as  the  largest 
and  most  highly  refined  steam  plant  can  do  it. 

As  centralization  of  small  steam  plants  has  been 
practised  in  the  interest  of  economy,  the  single  large 
plant  being  more  economical  than  the  many  small 
ones  it  displaces,  so  does  the  constant  efficiency  in  all 
sizes,  characteristic  of  the  gas-engine  plant,  tend  toward 
decentralization,  offering  to  the  factory  owner,  or  small 
power  user,  a  means  of  making  power  cheaper  than 
the  best  large  central  station  can  sell  it,  and  placing 
the  isolated  country  power  user  in  as  advantageous  a 
position  as  the  city  man  who  can  get  central  station 
power  if  he  wants  it.  The  gas-engine,  therefore,  is  the 
great  leveler  in  the  power  generation  field,  its  small 
and  insignificant  representative  playing  a  part  as  im- 
portant and  independent  as  its  more  aristocratic  large 
steam  or  water-power  rivals.  It  is  in  point  of  efficiency 
the  aristocrat  of  all  fuel  burners,  surpassing  in  its  few 
years  of  development  the  one  hundred  and  sixty  years' 
steam  product,  even  though  no  attempt  has  yet  been 
made  to  save  or  return  waste  heat  in  any  way. 


VII 


WATER-POWER    SYSTEMS    AND    BASAL   HYDRAULIC 
PROCESSES 

WHEREVER  rain  falls  streams  will  form,  the  water 
of  which  represents  the  concentrated  drainage  of  all 
the  land  sloping  toward  that  particular  valley  at  the 
bottom  of  which  the  stream  flows.  This  stream  flow 
consists  of  the  rainfall  over  the  whole  watershed  less 
the  amount  absorbed  by  the  earth,  or  evaporated  from 
the  surface,  and  every  such  stream  is  a  potential  source 
of  power.  The  possible  water-power  of  a  country  or 
district  is,  therefore,  primarily  dependent  on  rainfall, 
but  also,  of  course,  on  absorption  and  surface  evapora- 
tion. In  places  where  the  land  is  approximately  flat, 
the  tendency  to  concentrate  rainfall  into  streams 
would  be  small,  as  the  water  would  tend  to  lie  rather 
in  swampy  low  pools,  or  form  innumerable  tiny, 
slowly  moving  brooks.  On  the  contrary,  if  the  coun- 
try were  of  a  rolling  or  mountainous  character,  there 
would  be  two  important  differences  introduced.  First, 
water  would  concentrate  in  a  few  larger  and  faster- 
moving  streams,  the  water  of  which  would  represent 
the  collection  from  perhaps  thousands  of  square  miles; 
and  secondly,  it  would  be  constantly  falling  from 
higher  to  lower  levels  on  its  way  to  the  sea.  While, 
therefore,  all  streams  are  potential  or  possible  sources 
of  power,  and  water-power  might  seem  to  be  available 

211 


212  POWER 

all  over  the  earth,  yet,  as  a  matter  of  fact,  only  those 
streams  that  are  large  enough  or  in  which  the  fall  of 
level  is  great  enough,  are  really  worth  while  to  develop; 
and  only  in  those  districts  where  the  rainfall  is  great 
enough  and  the  earth  not  too  flat  or  too  absorbent, 
or  the  air  too  dry,  may  any  streams  of  useful  character 
at  all  be  expected.  The  power  represented  by  all  the 
water  of  a  stream,  and  its  entire  fall  from  the  source  to 
the  sea,  is  likewise  only  partly  available.  No  one  would 
think  of  trying  to  carry  water  in  pipes  from  the  source 
of  a  stream  a  thousand  miles  to  its  mouth  for  the  sake 
of  running  some  water-wheels. 

It  is  seldom  worth  while  to  carry  the  water  more  than 
a  mile  or  two,  and  frequently  even  this  would  not  pay, 
so  that  only  portions  of  streams  may  be  considered  as 
available  sources  of  power.  The  power  represented 
by  any  part  of  a  stream  is  directly  proportional  to  the 
product  of  the  quantity  of  water  flowing  per  second, 
and  the  difference  between  the  levels  at  the  beginning 
and  end  of  that  part  of  it  under  consideration,  which 
difference  in  level  is  called  the  " hydraulic  head."  Any 
portion  of  a  stream,  then,  in  which  there  is  a  difference 
of  head  may  be  considered  as  available  for  power,  the 
amount  of  which  is  measured  by  the  quantity  of  water 
flowing  and  the  head  itself.  Accordingly,  a  large  stream 
carrying  a  great  quantity  of  water,  which  falls  only  a 
little  in  level,  may  offer  only  a  small  power  possibility 
because  the  head  is  so  small,  whereas  a  comparatively 
small  stream,  perhaps  no  larger  than  a  brook  across 
which  a  boy  may  jump,  if  it  runs  down  the  side  of  a 
high  mountain,  may  make  available  at  the  foot  thou- 
sands of  horse-power  due  principally  to  the  head.  How- 


WATER-POWER  SYSTEMS  213 

ever  the  water  may  exist  naturally,  so  long  as  it  is 
in  the  form  of  a  stream  with  a  flow  from  a  high  level 
to  a  low,  it  offers  an  opportunity  for  power  generation 
by  concentrating  the  flow  on  wheels  of  suitable  form; 
but  it  may  easily  happen  that  the  returns  from  the 
development  may  not  be  worth  the  cost,  while  in  other 
cases  the  cost  of  development  may  be  richly  repaid. 
Even  though  the  water  itself  is  regarded  as  costing 
nothing,  and  therefore  as  offering  a  certainty  of  cheap 
power,  it  must  be  remembered  that  it  is  not  merely 
water  that  is  needed  for  power,  but  water  concentrated 
on  to  wheels,  sufficient  in  volume  and  sufficient  in  pres- 
sure when  it  reaches  the  wheel.  The  cost  of  the  water 
at  the  wheel  where  it  becomes  available  for  power  will, 
therefore,  be  measured  by  the  cost  of  the  concentration 
process.  Whether  it  will  be  worth  while  or  not  to  carry 
out  a  development  will  depend  entirely  on  the  ulti- 
mate cost  of  the  power  produced,  on  the  market  for 
that  power,  and  the  cost  of  competing  power  generated 
from  fuel.  No  one  would  be  justified  in  concentrating 
the  water  of  a  waterfall  into  wheels  if  the  cost  of  the 
power  exceeded  that  produced  from  fuel  by  the  steam 
or  gas  systems,  nor  would  it  be  a  sane  thing  to  develop 
a  power  in  the  heart  of  Africa,  where  there  is  no  demand 
for  power  within  five  hundred  miles,  no  matter  how 
cheaply  that  power  could  be  produced  at  the  spot. 
In  every  case  the  largest  item  in  the  cost  of  power  per 
horse-power  hour  or  per  horse-power  year  is  the  fixed 
investment  rate,  representing  the  interest  on  the  first 
cost  of  development  or  the  cost  of  diverting  the  stream, 
concentrating  its  flow  on  to  wheels,  and  providing  means 
of  control,  so  that  floods,  floating  ice,  and  logs  cannot 


214  POWER 

injure  the  works.  The  definite  yearly  per  cent  of  this 
development  cost  divided  by  the  power  produced 
gives  a  yearly,  monthly,  or  hourly  charge,  which  is 
the  largest  item  in  the  cost  of  water-power,  and  may 
even  be  larger  than  the  fuel  and  labor  cost  in  steam 
plants,  but,  of  course,  may  likewise  be  lower.  It  there- 
fore appears  that,  assuming  the  stream  to  be  available, 
representing  possible  power,  it  will  be  worth  while  to 
get  that  power  only  when  the  flow  is  large  with  perhaps 
moderate  head,  or  when  the  flow  is  small  with  large 
head,  and  when,  in  addition,  the  cost  of  diversion  and 
concentration  is  small  enough,  when  there  is  a  sufficient 
power  demand  or  selling  market  available,  and  finally, 
when  the  cost  of  steam  or  gas  power  is  high  enough 
in  that  particular  locality. 

It  usually  happens  that  the  cost  of  development 
does  not  stop  merely  with  diversion  and  concentration 
of  the  water  at  the  wheels,  because  rainfall  is  irregular, 
and  so,  of  course,  is  the  resulting  stream  flow,  which 
fact  introduces  a  necessity  for  storage  reservoirs.  The 
size  and  cost  of  these  storage  reservoirs  will,  of  course, 
depend  on  the  extent  of  the  fluctuation  of  stream  flow 
and  on  the  time  intervals.  A  district  in  which  there 
is  a  very  heavy  stream  flow  for  a  few  days,  followed  by 
a  month  of  no  flow,  would  require  a  reservoir  large 
enough  to  hold  practically  the  whole  flood  water  so 
that  it  could  be  supplied  uniformly  to  the  wheels  all 
the  rest  of  the  time.  Such  conditions  as  these  might 
be  found  in  tropical  countries,  where  there  are  heavy 
rains  extending  over  a  season,  followed  by  long  periods 
of  no  rain,  or  might  also  be  found  in  cold  countries 
where  during  the  winter  all  rainfall  is  frozen  into  ice 


WATER-POWER  SYSTEMS  215 

or  snow,  and  where  in  the  spring  there  comes  a  great 
rush  of  water  representing  the  concentrated  rainfall 
of  a  large  part  of  the  winter,  as  the  snow  and  ice  melts. 
No  two  streams,  representing  power  sources,  offer 
quite  the  same  problem  of  power  development,  the  first 
step  in  which  is  the  reaching  of  an  intelligent  judgment 
as  to  whether  it  would  be  worth  while  to  develop  at 
all  or  not,  which  judgment  must  be  based  on  the  most 
painstaking  investigation  of  a  multitude  of  conditions 
involving  rainfall,  stream  flow,  water  storage,  and 
power  demand  or  market,  together  with  estimates  of 
the  probable  cost  of  the  power  to  be  produced  and  the 
cost  of  competing  steam  or  gas  power.  Assuming  that 
it  has  been  found  to  be  worth  while,  and  it  must  be 
remembered  that  this  step  always  contains  an  element 
of  speculation,  the  next  step  is  to  decide  how  best  to 
carry  out  the  project  of  diversion,  concentration,  and 
storage  of  the  water-power  and  the  protection  of  the 
works  from  the  unused  or  flood  water,  from  ice  or 
floating  debris. 

Seldom  does  it  prove  worth  while  to  attempt  to 
develop  all  the  power  available  at  a  given  section  of 
a  stream,  because  the  cost  of  the  works  is  always  large ; 
and  if  the  installation  is  made  large  enough  to  use  the 
maximum  stream  flow,  then  in  time  of  drought  or 
freeze-up,  less  power  being  available,  a  part  or  perhaps 
all  of  the  investment  will  be  idle  and  earning  nothing; 
but  even  worse  than  this,  those  industries  dependent 
on  the  power  will  be  unable  to  proceed,  and  all  the  men 
employed  by  those  industries  will  be  thrown  out  of 
work,  thus  rendering  the  capital  invested  in  the  indus- 
tries also  useless.  To  protect  dependent  industries 


216 


POWER 


it  will  be  safe  to  develop  only  so  much  power  as  is 
represented  by  the  minimum  stream  flow,  and  to 
waste  all  the  rest  when  there  is  no  storage.  In  cases 
where  the  industry-demand  for  power  exceeds  this 
minimum  supply,  then  the  resource  of  a  storage  reser- 
voir is  available  to  a  limited  degree,  after  which  aux- 
iliaries, steam  or  gas  power,  must  be  installed,  further 
complicating  the  problem.  For  when  auxiliary  fuel- 
burning  power  is  used,  it  naturally  is  idle  in  times  of 


FIG.  164 

heavy  stream  flow,  which  fact  increases  the  cost  of  the 
power  delivered.  Furthermore,  it  might  easily  be 
far  better  for  dependent  industries  to  have  their  own 
steam  or  gas  plants  that  could  be  worked  all  the  time, 
instead  of  depending  on  a  combined  water  and  fuel 
plant,  part  of  which  must  certainly  be  idle  some  of  the 
time.  Such  difficulties  as  these  all  arise,  of  course, 
from  fluctuating  stream  flow,  which  is  violent  in  some 
places  and  practically  non-existent  in  others,  but  gen- 
erally present  to  a  sufficient  degree  to  make  a  good 
deal  of  trouble.  Streams  are  studied  by  engineers  and 


WATER-POWER  SYSTEMS  217 

government  officers  with  regard  to  their  flow,  and  the 
results  are  made  public  records,  either  in  the  form  of 
tables  or  curves,  as  shown  in  Fig.  164,  prepared  by  Pro- 
fessor Mead  to  illustrate  by  the  vertical  height  of  the 
irregular  line  the  variation  in  flow  for  each  month 
of  the  year  at  Kilbourn,  Wisconsin.  It  will  be  seen 
that  the  maximum  flow  is  approximately  seven  times 
the  minimum.  The  same  thing  is  shown  by  the  table 
prepared  by  J.  F.  Frizell,  showing  what  per  cent  of 
the  total  yearly  stream  flow  in  Massachusetts  is  avail- 
able for  each  month  of  the  year.  This  is  a  particularly 
striking  case  because  this  district  is  not  one  subject  to 
violent  storms  or  droughts. 

PER  CENT  OF  YEARLY  STREAM  FLOW  AVAILABLE  IN  EACH  MONTH 
OF  THE  YEAR  IN  MASSACHUSETTS 


January 16% 


February 14% 

March 20% 

April 15% 

May       10% 

June  .  4% 


July !     .     2% 


August     ......  3% 

September    .....  3% 

October    ......  5% 

November    .....  6  % 

December     .....  8% 


From  the  table  it  appears  that  the  minimum  flow 
occurs  in  July  and  is  only  one-tenth  of  the  maximum 
occurring  in  March,  when  the  snow  and  ice  are  melting. 
If  on  a  stream  of  this  character  power  development 
be  based  on  the  minimum  flow,  only  2  per  cent  of  the 
annual  flow  can  be  used  per  month,  or  24  per  cent  of  the 
total  in  the  year.  All  the  rest  must  be  wasted.  Even 
to  use  this  24  per  cent  of  the  yearly  rainfall,  storage 
reservoirs  must  be  available,  because  for  several  days 
at  a  time  the  actual  flow  may  fall  below  or  rise  above 
the  mean  for  the  month. 


218  POWER 

In  general,  stream-flow  fluctuations  are  least  when 
the  watersheds  feeding  this  stream  are  greatest  in  extent, 
because  rain  may  fall  in  one  section  and  not  in  another, 
the  average  for  all  being  steadier  than  for  any  one. 
Sometimes  these  watersheds  are  very  large.  To  illus- 
trate this  point,  the  following  table  is  presented  by 
Colonel  Samuel  Webber,  and  indicates  the  number  of 
square  miles  drained  for  each  of  three  sections  of  the 
Merrimac  River,  where  10,000  h.  p.  is  available. 

AREAS  OF  MERRIMAC  WATER  SHEDS 

Manchester  .  .  10,000  49  ft.  head  2709  sq.  mi.  watershed 
Lowell  .  .  .  10,000  331A  ft.  head  4000  sq.  mi.  watershed 
Lawrence  .  .  10,000  28  ft.  head  4600  sq.  mi.  watershed 

He  also  estimates  the  rainfall  for  the  United  States 
as  forty-two  inches,  about  half  of  which  gets  into  the 
streams,  representing  about  1,000,000  cubic  feet  per 
day  per  square  mile,  one-third  of  which  total  might  be 
conserved  by  reservoirs  if  the  cost  were  not  prohibi- 
tive, rendering  available  about  one  cubic  foot  per  sec- 
ond per  square  mile  on  the  average  for  the  whole  coun- 
try. Of  course,  much  of  this  rain  falls  on  low  land  and 
is  useless.  A  large  quantity  either  falls  on  dry  sections, 
or  the  streams  flow  through  dry  sections  where  the 
evaporation  is  very  severe.  Cases  are  known  where 
evaporation  from  a  pond  or  river  exceeds  the  equiva- 
lent of  one  inch  depth  per  day.  As  a  consequence  only 
a  very  small  portion  of  the  rainfall  is  really  available 
for  power  purposes;  but  by  careful  study  and  stimulated 
by  changes  in  industrial  and  economic  conditions,  more 
and  more  can  be  rendered  available  and  more  and  more 
than  is  now  used  may  be  profitably  developed. 


WATER-POWER  SYSTEMS  219 

The  study  of  water-power  conditions  is  very  old 
indeed,  but  it  is  only  for  the  past  fifty  years  or  so  that 
these  broad  aspects  of  the  question  of  economic  develop- 
ment, such  as  have  been  outlined,  have  received  atten- 
tion. The  recent  great  progress  is  due  partly  to  the 
fact  that  in  the  early  days  there  were  no  wheels  ca- 
pable of  using  high  heads ;  partly  to  the  lack  of  market 
for  power;  but  very  largely  because  many  of  the  most 
effective  water-power  sites  were  located  off  in  the  woods 
far  from  the  towns,  and  with  no  transportation  facilities 
between.  With  the  increasing  demands  for  power, 
due  to  the  development  of  manufacturing  and  largely 
stimulated  by  the  influence  of  the  steam-engine,  atten- 
tion was  directed  to  other  water-powers  than  those 
early  developed,  and  a  better  understanding  of  the 
principles  of  design  enabled  engineers  to  build  suitable 
high-head  water-wheels,  so  that  a  change  in  the  water- 
power  situation  was  inaugurated.  The  greatest  factor 
of  all,  however,  in  this  new  and  vigorous  utilization  of 
water-power  came  from  the  progress  in  electrical 
engineering,  which  showed  how  the  power  of  rotating 
shafts  could  be  converted  into  electrical  energy,  how 
such  electrical  energy  could  be  made  to  flow  without 
prohibitive  losses  or  excessive  costs  on  wires  over  dis- 
tances exceeding  100  miles,  and  how  at  the  end  of  a 
transmission  line  the  electrical  energy  could  be  con- 
verted back  into  the  form  of  rotating  shaft  power  by 
electric  motors,  or  converted  directly  into  light  by 
electric  lamps.  The  creation  of  electric  systems  of 
power  transmission,  consisting  of  generators,  line  wires, 
and  motors,  has  widened  the  limit  of  water-power 
application,  and  to-day  water-power  does  not  merely 


220  POWER 

exist  at  the  power  house,  but  in  fact  is  available  at  any 
point  within  a  circle  having  a  radius  of  one  hundred 
miles.  By  this  electrical  transmission  of  water-power, 
progress  in  water-power  generation  and  use  has  been 
stimulated  to  a  degree  that  otherwise  would  have  been 
impossible;  for  it  is  far  cheaper  to  run  wires  over  the 
mountains  to  towns  already  located,  and  in  commu- 
nication with  the  rest  of  the  world  by  river  or  railroads, 
than  to  run  railroads  through  mountain  countries  to 
permit  of  the  establishment  of  a  factory  at  the  water- 
power  site. 

As  a  result  of  this  latter  period  of  economic  develop- 
ment, the  practice  has  more  or  less  crystallized,  and  in 
reviewing  the  situation  as  it  exists  to-day  it  is  con- 
venient to  divide  those  cases  that  have  proved  to  be 
worth  while  into  three  typical  classes  with  regard  to 
the  head,  assuming,  of  course,  that  this  head  is  available 
within  not  too  great  a  horizontal  distance.  The  first 
class  will  include  low  heads  of  20  to  30  feet,  in  which 
case  there  would  nearly  always  be  involved  a  large 
quantity  of  water,  because  it  would  take  a  good  deal 
of  water  with  such  heads  to  develop  much  power.  The 
second  class  includes  medium  heads  between  100  and 
200  feet  and  with  perhaps  moderate  or  large  flow; 
and  the  third  class,  heads  up  to  or  exceeding  1000  feet, 
in  which  case  there  need  not  be  a  very  great  flow  to 
develop  considerable  power.  In  no  case,  as  has  already 
been  stated,  must  the  horizontal  distance  to  secure  this 
head  be  too  great,  and  in  practice  it  has  been  found 
that  the  abrupt  head,  such  as  occurs  at  falls  of  consid- 
erable height,  is  almost  ideal,  while  a  horizontal  dis- 
tance of  two  or  three  miles  is  not  out  of  the  question. 


WATER-POWER   SYSTEMS 


221 


FIG.  165 


To  illustrate  some  of  these  typical  cases  a  few  pictures 
will  be  helpful.  Perhaps  the  best-known  large-flow, 
abrupt-drop,  medium-head  site  is  that  of  Niagara 


FIG.  166 


222 


POWER 


Falls,  shown  in  Fig.  165,  taken  from  a  point  above  the 
Falls  and  showing  more  particularly  the  great  volume 
of  water  and  the  width  of  the  fall.  At  this  point  the 
fall  varies  in  height  from  158  to  167  feet,  and  the  width 
of  the  crest  is  about  one-half  mile,  over  which  the 

volume  of  the  flow  is 

not  exactly  uniform. 
It  is  estimated  that 
about  7,000,000  h.  p. 
is  available  at  this 
point,  of  which  only  a 
small  portion  is  devel- 
oped or  under  con- 
sideration. Another 
view  of  the  Falls,  taken 
from  the  gorge  below 
some  distance  away, 
and  showing  some  of 
the  industrial  plants 
that  have  grown  up  by 
reason  of  the  power,  is 
shown  in  Fig.  166.  In 
this  view  a  vertical 
pipe-line  is  clearly  visi- 
ble, conducting  water  from  above  to  a  power  house  below, 
where  the  head  available  is  about  220  feet,  and  by  means 
of  which  some  1500  h.  p.  is  developed.  Part  way  up 
the  cliff,  water  can  be  seen  spouting  from  the  discharge  of 
several  water-wheels  using  only  part  of  the  head  and  so 
wasting  some  of  the  power.  Another  example  of  a  still 
greater  falls  of  much  the  same  character  as  Niagara  is 
shown  in  Fig.  167,  representing  the  great  cataract  of  the 


FIG.  167 


WATER-POWER  SYSTEMS 


223 


Zambesi  in  Africa,  still  undeveloped  because  of  lack  of 
market  or  demand  for  power  in  that  locality,  although 
many  projects  have  been  formulated,  some  of  which 
will  ultimately  be  carried  out.  The  illustration 
shows  clearly  the  abrupt  character  of  the  drop,  and 
the  indications  of  the  variable  flow  which  charac- 
terizes this  stream,  in  ( ^ 

striking  contrast  to  the 
almost  uniform  flow  of 
Niagara.  Here  the 
height  is  a  little  over 
400  feet,  and  it  is  esti- 
mated that  in  time  of 
flood  over  35,000,000 
h.  p.  may  be  secured; 
but  by  reason  of  the 
tropical  and  irregular 
character  of  the  rain- 
fall, only  a  small  frac- 
tion of  this  can  be  de- 
pended upon  for  steady 
generation.  Another 
example  of  the  same 
class  of  abrupt  fall,  but 
much  smaller,  though  FIG.  IBS 

still  large,  is  shown  in 

Fig.  168,  which  is  a  view  of  the  Montmorency  Falls, 
about  eight  miles  from  Quebec,  where  there  is  now  in 
use  some  12,000  h.  p.  under  a  head  of  275  feet.  Part 
of  the  head  works  and  gate-houses  through  which  the 
water-power  is  diverted  are  visible  at  the  top  of  the 
picture.  An  example  of  the  somewhat  scattered  but 


224 


POWER 


still  fairly  high,  though  not  so  abrupt,  fall  is  shown 
in  Fig.  169,  representing  the  city  of  Tivoli,  Italy,  where 
there  is  a  head  of  360  feet,  of  which,  however,  only 
165  feet  is  used  and  some  2000  h.  p.  developed.  The 
city  above  the  falls  is  clearly  visible  at  the  top  of  the 
picture.  These  few  examples  will  serve  to  illustrate 
that  type  of  stream  in  which  the  volume  of  water  is 


FIG.  169 

considerable,  the  fall  obtained  in  a  very  short  hori- 
zontal distance,  and  the  head  of  intermediate  value, 
offering  almost  ideal  conditions  for  power  development. 
Extremely  high  heads  are  available  only  in  the  moun- 
tains and  obtainable  only  by  more  or  less  considerable 
horizontal  distances.  Development  in  these  cases  will, 
therefore,  cover  some  miles  of  mountainous  country, 
often  involving  the  boring  of  rock  tunnels  and  the 
construction  of  canals  carrying  water  around  the  sides 
of  hills,  so  that  no  single  picture  can  quite  show  the 
nature  of  the  problem.  There  is,  however,  presented 


WATER-POWER   SYSTEMS 


225 


in  Fig.  170  a  view  of  a  pipe-line  coming  down  the  side 
of  a  high  mountain  and  forming  part  of  one  of  these 
high-head  plants.  This  pipe-line  has  been  installed  by 

the  San  Joaquin  Electric  Co.  of     

Fresno,  California,  to  develop 
a  head  of  1400  feet,  and  1000 
h.  p.  is  transmitted  electrically 
35  miles  over  the  mountains. 
This  pipe-line  is  fed  by  a  canal 
seven  miles  long,  the  pipe  itself 
being  4000  feet  in  length,  in- 
dicating that  a  distance  of 
seven  miles  was  necessary  to 
develop  this  head,  a  condition 
which  would  never  have  been 
justified  unless  so  great  a  head 
could  be  available.  Such  high- 
head  work  through  mountain- 
ous country  is  characteristic  of 
our  own  Rocky  Mountains, 
parts  of  Mexico,  and  the  Swiss 
Alps,  and  is  a  direct  result  of 
the  influence  of  electrical  trans- 
mission, without  which  these 
isolated  and  inaccessible  moun- 
tain streams  would  have  been 
quite  useless. 

The  last  of  the  three  classes 

of  streams  and  that  first  developed  is  the  low-head 
class,  where  either  at  a  low  natural  waterfall,  or  at 
the  head  of  a  section  of  the  river  where  there  are 
rapids,  a  dam  is  placed,  fixing  a  high  level  for  the 


FIG.  170 


226 


POWER 


water,  the  low  point  being  located  at  some  convenient 
spot  down-stream,  perhaps  only  a  few  feet  or  per- 
haps several  miles  away.  Such  a  stream  is  illustrated 
in  Fig.  171,  which  represents  the  German  Rhine  at 
Neuhausen.  Here  the  river  runs  through  a  sloping 
stretch,  making  a  rapid.  Another  stream  having  a 
similar  rapids  section  is  the  Susquehanna  River, 


FIG.  171 

recently  developed  at  McCall's  Ferry,  at  which  point 
the  river  is  2700  feet  wide,  and  drains  an  area  in 
the  Alleghanies  of  27,400  square  miles.  The  erec- 
tion of  a  dam  has  made  available  a  head  of  53  feet, 
which,  of  course,  varies  from  time  to  time.  In  time  of 
flood  the  flow  of  water  is  225  times  as  much  as  the 
minimum  flow.  This  requires  a  large  waste  weir,  or 
overflow  dam,  2500  feet  long,  over  the  crest  of  which 
the  flood  waters  will  rise  17  feet.  To  indicate  the 


WATER-POWER  SYSTEMS 


227 


power  market  that  has  warranted  this  development 
it  should  be  noted  that  within  a  radius  of  seventy  miles 
are  located  the  cities  of  Philadelphia,  Wilmington, 
Baltimore,  Harrisburg,  York,  and  Lancaster,  for  which 
there  will  be  available  by  ten  wheels  about  140,000  h.  p. 
The  Susquehanna  development  is  shown  in  Fig.  172, 
which  is  a  map  of  the  section.  A  photograph  illustrat- 
ing the  magnitude  of  the  construction  work  necessary 


to  the  dam  is  shown  in  Fig.  173,  while  the  flood  diffi- 
culties are  shown  in  Fig.  174,  representing  a  flood  through 
a  partly  completed  section  of  the  dam,  submerging 
much  of  the  construction  equipment  there  located. 
Still  another  case  of  low-head  development  is  that  on 
the  Tennessee  River  below  the  city  of  Chattanooga, 
the  location  of  which,  with  respect  to  the  dam,  is  shown 
on  the  map  (Fig.  175),  from  which  it  will  appear  that 
the  dam  is  many  miles  below  the  city,  while  the  stream 
runs  through  sections  of  low  land  and  through  narrow 
valleys  between  high  banks.  The  creation  of  the  dam 


226 


POWER 


FIG.  173 

causes  the  water  to  rise  in  this  stream  for  some  thirty 
miles  above,  although  the  head  is  available  through 
the  abrupt  fall  created  at  the  dam  itself. 

In  the  early 
days  of  Ameri- 
can develop- 
ment only  low 
heads  were  at- 
tempted, and  on 
the  sites  chosen 
cities  grew. 
These  low  heads 
were  selected 
because  of  the 
prevailing  form 
Fl«-  174  of  water-wheel, 


WATER-POWER  SYSTEMS 


229 


which  was  the  familiar  old  mill  overshot  or  breast  type, 
completely  exposed  and  of  diameter  approximating  the 
height  of  the  falls.  These  wheels  were  located  first  at 
either  the  side  of  a  natural  fall  or  at  one  end  of  a  dam  built 
above  a  fall  or  rapids.  When  more  power  was  wanted, 
another  mill  with  its  wheel  was  located  at  the  other 
end  of  either  the  fall  or  the  dam;  and  when  more  than 
this  supply  was  wanted,  there  began  canal  construction. 
A  canal  was  excavated  on  the  high  ground  on  a  level 


FIG.  175 

with  the  upper  waters,  and  sometimes  also  another  one 
through  the  low  ground  at  a  level  with  the  lower  waters. 
Between  these  two  canals  any  number  of  wheels  could 
be  located  and  any  number  of  mills  established.  Where 
the  ground  was  sloping  between  the  high  and  low-level 
canals,  wooden  boxes  or  flumes  were  built  out  and 
supported  on  posts  to  bring  the  water  directly  over  the 
wheel,  from  which  it  discharged  into  the  tail  canal. 
In  those  cases  where  the  head  was  so  high  as  to  demand 
very  large  wheels,  say  30  feet  in  diameter,  another 


230 


POWER 


CONNECT/CUT 


intermediate  canal  was  built,  and  smaller  wheels,  of 
half  the  diameter,  located  at  intermediate  points.  The 
water  from  the  high-level  canal  would  run  from  one 
wheel  into  the  intermediate  canal,  and  from  there  to 
a  second  wheel  into  the  low  level.  This  sort  of  develop- 
ment was  carried  on  for  many  years  and  was  the  first 
attempt.  According  to  Colonel  Samuel  Webber,  the 
first  water-wheel  to  be  erected  in  this  country  was 
built  in  1790  at  Pawtucket  Falls,  for  cotton  manufac- 
ture, and  was 
soon  followed 
by  others  at 
Paterson,  New 
Jersey,  in  1813 
at  Fall  River, 
Massachusetts, 
and  in  1821  on 
the  Merrimac 
River  for  oper- 
ating both  a 
machine  shop  and  a  cotton-mill  at  a  point  which  after- 
wards became  the  city  of  Lowell.  At  the  point  on  the 
Merrimac  River  the  two-canal  system  was  used,  with 
two  drops  of  13  and  17  feet  respectively,  to  accommo- 
date the  small  wheels  to  the.  30-foot  head.  A  similar 
canal  development,  but  with  three  levels,  took  place 
at  a  point  in  the  Connecticut  River  where  is  now  lo- 
cated the  city  of  Holyoke,  Massachusetts.  The  ar- 
rangement of  these  canals  is  shown  on  the  map,  Fig.  176. 
At  this  point  there  is  a  total  head  available  of  61  feet, 
developed  for  a  distance  of  3250  feet  below  the  dam, 
where  there  are  now  at  work  some  60  mills,  using  about 


FIG.  176 


WATER-POWER  SYSTEMS  231 

30,000  h.  p.  by  day,  and  half  as  much  at  night.  Per- 
haps the  first  tendency  toward  the  changing  of  con- 
ditions was  the  result  of  steam  competition,  which 
appeared  in  1830,  at  which  time  the  first  steam-engine 
mill  was  erected  at  Providence,  Rhode  Island,  and  it 
is  an  open  question  whether  this  competition  did  or 
did  not  tend  to  stimulate  the  study  of  water-power; 
but  whether  it  did  or  not  there  was  applied  fourteen 
years  later,  at  the  Appleton  Mills  in  Lowell,  1844,  the 
first  hydraulic  turbine.  This  turbine,  typical  of  all 
future  development,  was  capable  of  making  more  effec- 
tive use  of  any  head  of  water  than  were  the  old  wheels; 
and  it,  moreover,  could  be  built  for  high  as  well  as  low 
heads,  and  could  be  supplied  with  water  through  pipes 
over  or  under  ground,  making  canals  unnecessary,  except 
in  those  cases  where  they  were  already  installed,  or 
where  their  construction  was  cheaper  than  pipe-lines 
of  the  same  water  capacity.  These  turbines  make 
use  of  the  spouting  capacity  of 
water  under  pressure  as  it  issues 
from  the  pipe  or  nozzles  con- 
nected with  the  pipe.  The 
water-jet,  as  already  explained, 
works  in  connection  with 
curved  vanes,  operating  them 
by  giving  up  its  velocity,  an 
action  which  distinguishes  FIG  1? 

them  from  the  old  and  most 
common  overshot  wheels,  where  the  water  turns  the 
wheel  by  its  weight  alone.  It  is  worth  while  to  review 
the  principles  of  these  turbines,  which  had  the  effect  of 
changing  water-power  development  methods,  and  which 


232 


POWER 


were  not  built  in  this  country  until  1844.  In  Fig.  177 
is  shown  a  crude  Indian  affair,  acting  by  impulse. 
Water  issuing  from  the  wooden  pipe  has  a  certain 
velocity  and  direction,  and  by  impulse  on  the  wooden 
vanes  turns  the  wheel.  A  more  recent  form  and  better 
design,  though  still  an  old  one,  is  shown  in  Fig.  178, 
in  which  gates  are  provided 
to  control  the  water.  The 
spout  is  tapered  to  get  a 
better  form  of  jet  and  the 
vanes  are  curved  to  get 
better  effect  on  the  wheels. 


Elevation. 


FIG.  178 


Plan  and  Partial  Section. 
FIG.  179 


This  design  is  fundamental  to  the  modern  impulse 
wheel.  A  similar  simple  wheel  of  earlier  times,  con- 
taining the  essentials  of  the  modern  reaction  wheel, 
is  shown  in  Fig.  179,  in  which  the  water  is  brought 
to  the  hollow  interior  of  the  wheel  by  a  pipe  leading 
upward  to  its  center.  Water  escapes  from  the  hollow 


WATER-POWER  SYSTEMS  233 

interior  through  nozzles  bent  so  as  to  make  the  dis- 
charge tangential  and  rotating  the  wheel  by  reaction. 
Modern  water-wheels  designed  with  nozzles  and  curved 
vanes  act  on  both  reaction  and  impulse,  and  sometimes 
by  both  in  the  same  wheels,  and  are  no  more  than  re- 
finements of  these  simple  affairs  which  started  a  move- 
ment completely  revolutionizing  water-power  develop- 
ment some  years  ago.  In  order  to  show  clearly  how 


FIG.  180 

the  turbine  installation  compares  with  the  overshot 
water-wheel  installation,  which  it  began  to  replace 
at  that  time,  there  is  presented  Fig.  180.  Here  there 
are  two  parallel  installations  for  the  same  head  of  water, 
the  water  being  carried  from  the  stream  to  the  wheels 
through  an  open  wooden  box  or  flume.  It  will  be 
observed  that  the  overshot  wheel  spills  most  of  its 
water  part  way  down,  so  that  the  water,  which  acts 
only  by  its  weight,  is  available  for  only  part  of  the  fall, 


234 


POWER 


in  fact,  only  a  very  small  portion  of  it  is  available  for 
all  of  the  fall.  For  the  turbine  a  vertical  box  is  at- 
tached to  the  flume,  and  at  its  bottom  all  the  water 
escapes  through  jets  in  the  turbine  with  a  velocity  due 
to  the  whole  head  or  fall,  so  that  if  the  vanes  are  rightly 
formed  and  run  at  the  right  speed,  fully  80  per  cent  of 

the  possible  effect 
can  be  obtained. 
Moreover,  the 
water  could  have 
been  brought  to 
the  turbine  by  a 
pipe  over  the  whole 
distance  instead  of 
by  canals,  thus 
making  possible 
great  flexibility  of 
construction,  no 
matter  what  the 
head.  Modern 
turbines  are  care- 
fully designed  and 
somewhat  elabo- 
rate machines, 
especially  when 

they  are  built  to  run  electric  generators,  which  require 
great  steadiness  of  motion  accomplished  only  by 
very  elaborate  governing  apparatus  in  addition  to 
fine  design.  A  few  examples  of  these  will  be  shown 
to  indicate  general  form  and  appearance,  but  the 
principles  of  detailed  design  are  too  technical  to  be 
gone  into  here.  In  Fig.  181  are  shown  three  small  tur- 


FIG.  181 


WATER-POWER  SYSTEMS 


235 


bines  on  vertical  shafts  as  they  appeared  in  the  shop, 
inlet  and  discharge  pipes  being  clearly  shown.  The 
largest  turbine  ever  built,  and  designed  also  for  a  ver- 
tical shaft  operation,  is  shown  in  Fig.  182,  the  size  of 
which  may  be  judged  by  comparing  with  the  ladder  at 
the  left,  which  is  faintly  visible.  It  develops  18,000 


FIG.  182 

h.  p.  in  a  single  wheel,  and  is  one  of  four  built  by  I.  P. 
Morris  Co.  for  Great  Western  Power  Co.,  for  525  feet 
head  and  nearly  90  per  cent  efficiency.  This  particular 
picture  is  interesting  by  reason  of  the  fact  that  there 
is  clearly  visible  at  the  top  of  the  machine  a  series  of 
levers  operating  the  gates  for  closing  off  the  water 
which  enters  the  pipe  shown  and  so  regulating  the  power. 
These  levers  are  all  attached  to  a  ring  having  two 


236 


POWER 


lugs  at  opposite  points  on  .tba  side,  to  which  are  at- 
taghed  the  rods  of  two  hydraulic  pistons.  By  supply- 
ing pressure  water  to  these  cylinders,  the  pistons,  rods, 
and  levers  may  be  moved,  and  this  movement  is  con- 
trolled by  the  speed  of  the  machine  through  a  governor. 
These  gates  are  rather  heavy  in  large  machines  and 
offer  considerable  resistance  to  opening  and  closing, 


FIG.  183 

and  it  is  for  this  reason  that  hydraulic  cylinders  like 
these  are  provided  to  utilize  the  water  pressure  to 
accomplish  the  change  of  gate  position.  A  smaller 
machine,  designed  for  a  horizontal  shaft  and  also  com- 
pletely cased  in,  is  shown  in  Fig.  183.  Here  the  hy- 
draulic cylinders  are  also  present  but  the  gate  levers  are 
not  visible.  Another  horizontal  shaft  machine  is  shown 
in  Fig.  184,  in  which  the  wheel  proper  is  exposed  beyond 


WATER-POWER   SYSTEMS 


237 


FIG.  184 

the  casing.  This  particular  machine  is  capable  of 
developing  some  200  h.  p.  under  a  head  of  30  feet,  and 
is  built  for  the  Hanford  Irrigation  &  Power  Co.  in  the 
state  of  Washington,  by  the  Allis-Chalmers  Co.  The 
wheel  proper,  or  runner,  of  one  of  another  type  of 

turbine  is  shown  in  Fig.  185,     • 

from  which  it  will  be  clear 
that  the  vanes  are  sometimes 
quite  complicated  and  curi- 
ously curved,  and  yet  these 
curvatures  are  very  carefully 
worked  out  on  hydraulic  prin- 
ciples. Two  turbines  provided 
with  wheel  runners  of  this 
kind  just  mentioned,  built  by 
the  Samson  Co.,  are  illustrated 
in  Fig.  186,  one  of  which  is 
provided  with  a  casing  com- 
plete, while  the  other  is  only 

partly   cased.      In   the   latter     

form  the  water  supply  is  not  FIG.  185 


238 


POWER 


FIG.  186 


piped  to  the  wheel,  although  the  discharge  is  piped  away. 
A  large  wheel  of  this  same  construction,  designed  to 
operate  in  one  of  the  plants  of  the  Niagara  Falls  Power 
Co.,  is  shown  in  Fig.  187,  and  develops  1500  h.  p.  under 


FIG.  187 


WATER-POWER  SYSTEMS  239 

a  head  of  220  feet.  An  extremely  large  wheel,  designed 
for  a  vertical  shaft  and  developing  13,000  h.  p.,  is  shown 
in  Fig.  188  as  designed  for  the  Electrical  Development 


FIG.  188 


Co.  of  Ontario.  As  a  matter  of  fact,  this  wheel  is  two 
wheels  within  one  casing,  each  receiving  water  from 
the  same  pipe,  shown  in  the  background,  and  both 


240 


POWER 


discharging  to  the  center  to  a  common  discharge  pipe, 
shown  at  .the  right.  This  is  one  of  eleven  installed  at 
Niagara  Falls  for  a  head  of  135  feet,  each  supplied 
through  riveted  steel  pipes  10  feet  6  inches  in  diameter. 
From  the  constructions  shown  it  will  appear  that 
the  water  may  be  led  to  these  turbines  through  pipes, 
or  they  may  be  submerged  in  the  head  waters  above 
the  dam ;  they  may  be  run  with  vertical  or  horizontal 
shafts;  all  have  vanes  and  nozzles,  although  the 
nozzles  may  themselves  look  like  vanes,  as  is  the  case 
with  steam-turbines.  The  direction  of  flow  may  be 
up  or  down,  in  or  out,  in  practically  any  convenient 
way,  making  their  application  by  reason  of  this  flexi- 
bility a  comparatively  easy  thing.  In  all  cases  the  water 
acts  over  the  whole  circumference  of  the  wheel,  and 
whether  it  enters  through  guide  vanes  to  ultimately 
discharge  through  nozzles,  as  in  reaction  wheels,  or 
enters  nozzles  directly  to  strike  vanes  later,  as  in  im- 
,  pulse  wheels,  the 

nozzles  themselves 
form  a  continuous 
ring  and  are  made 
-j— —f~  by  inserting  parti- 
tions of  suitable  form 
between  plates;  the 
water  spaces  between 
the  partitions  con- 
stitute the  nozzles. 
To  regulate  the  quantity  of  water  passing  through  these, 
nozzles  gates  are  always  provided,  and  a  water-wheel 
that  is  not  provided  with  gates  for  regulating  it  is  prac- 
tically useless  for,  electrical  operations,  as  control  of 


FIG.  189 


WATER-POWER   SYSTEMS 


241 


speed  is  quite  essential.  These  gates  are  of  three 
classes,  known  as  cylinder  gates,  register  gates,  and 
wicket  gates.  In  Fig.  189  is  shown  a  wheel  provided 
with  register  gates.  These  register  gates  are  really  a 
series  of  specially  formed  covers  that  slide  over  the 
nozzles  of  the  wheel  by  a 
movement  about  the  circum- 
ference. In  the  figure  the 
gates  are  shown  in  three  dif- 
ferent positions.  In  the  upper 
right-hand  position  the  nozzles 
are  completely  closed.  In  the 
upper  left-hand  position  the 
nozzles  are  partially  open.  In 
the  lower  left-hand  posi- 
tion they  are  completely 
open.  To  move  these 
gates  around  so  that  they 
cover  or  uncover  the  ori- 
fices, a  ring  is  provided 
with  gear  teeth  and  a 
small  gear  attached,  as 
shown  in  the  lower  left- 
hand  corner.  Instead 
of  sliding  something 
around  the  circumference  to  close  the  opening,  as  is 
done  with  the  register  gate,  a  thin  cylindrical  shell, 
somewhat  like  a  piece  of  pipe,  may  be  slipped  in 
between  the  fixed  and  moving  part  of  the  turbine,  as 
is  shown  in  Fig.  190,  which  represents  a  cross-section 
of  one  of  the  5500  h.  p.  turbines  of  the  Niagara  Falls 
Power  Co.  The  two  heavy  black  lines  at  the  center 


FIG.  190 


242 


POWER 


represent  a  section  of  the  cylinder  gate  plate.  By 
lifting  this  cylindrical  shell  up  and  down,  the  size  of 
the  water-passage  may  be  controlled.  Instead  of 
lifting  a  cylinder  up  or  down,  as  is  done  with  the 
cylinder  gate,  or  instead  of  sliding  a  row  of  covers 
over  the  nozzles,  as  is  done  in  the  register  gate,  curved 
partitions  may,  as  in  the  wicket  gate,  be  pivoted. 
Such  a  wicket  gate  is  shown  in  Fig.  191  attached  to  a 
small  100  h.  p.  turbine  of  Swiss  design.  Each  partition 
is  formed  somewhat  like  a  shoe  and  has  a  pivot  at  its 

center.  By  ro- 
tating each  about 
this  central  pivot 
the  space  be- 
tween may  be 
made  narrow  or 
wide,  but  still 
will  constitute  a 
nozzle  directing 
the  water  in  approximately  the  same  desired  direction. 
The  movement  of  these  gates,  whether  they  be  cylinder, 
wicket,  or  register  type,  is  always  under  the  control  of 
governors,  which  are  themselves  quite  complicated 
machines,  one  of  which  is  shown  in  Fig.  192,  the 
details  of  which  need  not  be  gone  into  here;  but  it 
must  be  realized  that  governing  is  an  important  factor 
in  successful  water-power  work,  and  that  it  is  a  difficult 
problem. 

When  gates  are  closed  to  reduce  the  quantity  of 
water  passing  through  the  wheel,  the  whole  quantity 
of  water  in  the  pipe  must  be  reduced  in  speed.  This 
water  is  practically  incompressible,  and  the  slowing  up 


FIG.  191 


WATER-POWER  SYSTEMS 


243 


of  this  long  column  without  danger  is  just  as  difficult 
a  proposition  as  stopping  a  high-speed  train.  If  gates 
be  suddenly  closed  at  the  end  of  a  long  pipe-line,  the 
water  will  tend  to  continue  to  move  by  its  own  inertia, 
so  that  the  pressure  at  the  gate  will  momentarily  rise, 
and  may  become  very  high,  so  high,  perhaps,  as  to  burst 
the  pipe  or  injure  the  wheel.  In  the  case  of  the  Fresno 


FIG.  192 

Power  Plant,  already  referred  to,  the  weight  of  the  water 
contained  in  the  4000  feet  of  pipe,  having  diameters 
at  the  beginning  24  inches,  and  20  inches  at  the  end, 
is  317  tons.  If  the  gates  were  suddenly  closed  on  this 
pipe-line,  the  317  tons  of  water  would  be  suddenly 
stopped,  and  something  would  happen,  and  that  some- 
thing would  mean  a  wreck,  unless  the  pipe  were  made 
unusually  thick,  or  some  safety  element  provided. 


244 


POWER 


To  avoid  this  difficulty  relief- valves  are  sometimes 
used,  something  like  the  safety-valves  on  boilers,  but 
they  are  not  considered  as  reliable  as  another  device, 
which,  however,  cannot  be  used  on  very  high  heads. 
This  other  device  is  a  stand-pipe  projecting  up  in  the 
air  near  the  power  house.  Under  ordinary  flow  con- 
ditions the  water  would  not  run  out  at  the  top,  but 

, ,    should  the  flow  of  water 

be  suddenly  arrested, 
the  water  would  spout 
out  at  the  top,  as  shown 
in  Fig.  193,  illustrating 
two  stand-pipes,  one  of 
which  is  discharging 
water,  and  the  other 
is  not. 

The  horse-power  of 
a  turbine  is  some  frac- 
tion of  the  product  of 
the  quantity  of  water 
flowing  and  its  head  or 
pressure.  This  frac- 
tion is  the  efficiency, 
or  the  ratio  of  the 
power  that  the  turbine  can  develop  to  the  energy  of 
the  water  passing  through,  and  in  good  wheels  this 
is  about  80  to  90  per  cent.  The  area  of  the  passages 
through  which  the  water  flows  must  be  large  enough 
to  pass  just  the  right  amount  of  water,  so  that  for  low- 
head  work,  when  much  power  is  to  be  developed,  the 
orifices  must  be  large,  and  the  water  passages  in  the 
wheel  also.  On  the  contrary,  for  very  high-head  work 


FIG.  193 


WATER-POWER  SYSTEMS 


245 


the  quantity  of  water  needed  to  develop  the  same  power 
is  very  much  less,  so  that  the  areas  of  the  nozzle  passages 
must  be  quite  small.  As  a  matter  of  fact,  for  very 
high  heads,  approaching  1000  feet,  a  wheel  of  suitable 
diameter  would  require  a  total  nozzle  area  too  small 
to  permit  of  construction  and  control  if  the  nozzles 
extended  all  around  the  circumference  of  the  wheel, 
as  each  nozzle  will  be  a  mere  slit  no  wider  than  the  blade 
of  a  knife.  Therefore,  for 
high-head  work  all  the  water, 
instead  of  entering  the  wheel 
over  the  whole  circumference, 
is  concentrated  in  one,  two,  or 
three  nozzles,  generally  one 
directed  toward  the  wheel, 
which  is,  therefore,  always  of 
the  impulse  type.  These  high- 
head  wheels,  designed  for  single 
nozzles,  are  differently  formed 
from  the  other  turbines  noted, 
and  consist  of  disks  carrying 
on  their  circumferences  a  series 
of  buckets,  such  as  shown  in 
Fig.  194,  which  illustrates  a  wheel  to  develop  500  h.  p. 
at  a  head  of  865  feet.  A  series  of  impulse- wheels  of 
the  same  general  class,  but  differing  structurally,  is 
shown  in  Fig.  195,  as  installed  in  the  San  Joaquin 
plant,  the  jet  striking  the  buckets  of  the  wheels 
underneath.  To  control  the  speed  of  these  wheels 
and  at  the  same  time  to  avoid  setting  up  heavy  inertia 
pressures  in  the  pipe-line  by  varying  the  quantity  of 
water,  it  has  become  customary  to  deflect  the  nozzles  so 


FIG.  194 


246 


POWER 


that  the  jets  strike  the 
buckets  more  or  less. 
Such  an  arrangement 
is  shown  in  Fig.  196, 
in  which  the  nozzle  is 
carried  from  a  lever 
controlled  by  the  gov- 
ernor, so  that  when  the 
speed  gets  too  high  the 
nozzle  is  dropped  away 
from  the  wheel.  This 
allows  the  regulation  of 
speed  desired,  without 
varying  the  quantity 
of  water,  and  therefore 
injuring  the  pipe.  It 
is  interesting  to  note 

in  this  connection  how  concentrated  is  the  jet.  Such 
a  jet  is  shown  in  Fig.  197.  It  looks  like  a  bar  of 
polished  steel,  and  if  directed  against  a  man  would 
pierce  his  body,  as  would  a  projectile  from  a  gun. 


FIG.  195 


FIG.  196 


WATER-POWER   SYSTEMS 


247 


It  is,  therefore,  a  thing  to  be  carefully  guarded  and 
perfectly  controlled. 

Wheels  being  available  for  any  head,  however  "gfeat 
or  small,  and  a  locality  likewise  available  for  a  flow  of 
water  with  a  suitable  head  that  can  be  developed 
within  a  reasonable  distance,  small  if  the  head  is  low, 
large  if  it  is  high,  the  problem  becomes  how  best  to 
adapt  the  wheel  to  the  locality,  or  how  best  to  modify 
the  locality  to  receive  the  wheel ;  the  modification  in 
every  case  involving 
concentration  of  the 
flow  of  water,  or  as 
much  of  it  as  is  to  be 
used,  the  providing  of 
storage  to  take  care  of 
fluctuations  in  the  flow, 
and  the  providing  of 
safeguard  against  the 
destruction  of  the 
wheels.  Unless  there 
is  a  direct  fall,  there 

must  be  a  dam,  the  object  of  which  is  to  fix  the  high 
level  and  to  store  water.  In  connection  with  the  dam 
there  should  be  at  one  side,  or  at  some  other  point  in 
the  stream,  a  spillway  over  which  waste  water  coming 
down  in  time  of  excess  of  supply  or  of  flood  may  flow 
without  injuring  the  plant.  At  Niagara,  the  falls  them- 
selves constitute  a  natural  spillway,  whereas  at  McCall's 
Ferry,  as  has  been  noted,  there  was  required  a  half-mile 
spillway  dam.  Dams  are  made  in  all  sorts  of  ways,  from 
earth  and  rock  reinforced  by  timber,  from  masonry,  or 
from  concrete  running  down  to  bed-rock,  and  may,  there- 


FIG.  197 


248 


POWER 


FIG.  198 


fore,   be  cheap  or  expensive.     They  may  vary  from 
only  a  few  hundred  feet  in  width  to  nearly  a  mile. 

A  timber  and 
cribwork  dam 
of  the  Animas 
Co,,  in  southern 
Colorado,  is 
shown  in  Fig. 
198.  At  this 
point  about 
4000  h.  p.  is 
developed  with 
a  head  of  ap- 
proximately 
1000  feet.  The 
water  is  led 
from  Cascade  Creek  to  this  dam  through  a  wooden 
flume,  the  reservoir  back  of  the  dam  covering  about 

960   acres,   the    , , 

dam  itself,  550 
feet  long,  75  feet 
high,  extending 
33  feet  down  to 
rock.  Another 
dam,  built  of 
concrete  with 
stone  spillway, 
is  shown  in  pro- 
cess of  erection 
in  Fig.  199  on 
the  Chattahoochee  near  Columbus,  Georgia.  This 
dam  is  33 J  feet  above  bed-rock,  and  controls  a  head 


FIG.  109 


WATER-POWER  SYSTEMS 


249 


of  40  feet,  at  which  some  25,000  h.  p.  will  be  devel- 
oped from  the  drainage  of  3500  square  miles.  From 
above  the  dam,  or  natural  water  basin,  if  there  is 
one  instead  of  the  dam,  the  water  is  led  to  the  wheels 
in  a  great  variety  of  ways.  The  wheels  may  even  be 
within  the  dam  itself,  the  casing  being  removed  from 
the  supply  side  and  the  inlet 
orifices  exposed  to  the  stand- 
ing water;  or  the  water  may 
be  led  through  wooden  flumes, 
masonry  canals,  rock  tunnels, 
or  vertical  shafts  bored  in  the 
rock,  or  through  iron  or  wooden 
pipes.  Somewhere  in  the  open 
conduit  there  is  usually  pro- 
vided a  sort  of  basin  called  a 
forebay,  to  which  the  head- 
gates  are  attached,  so  that 
the  water  may  be  shut  off  for 
repairs  ;  there  will  also  be 
placed  at  this  point  rubbish 
or  ice  racks  to  intercept  float- 
ing ice  or  logs.  Whenever 
there  is  an  upper  level  canal  it 

is  called  a  head-race.  Below  the  wheels  a  canal  is 
needed  sometimes  to  reach  the  lower  level  waters,  and 
in  such  cases  it  is  called  a  tail-race.  Before  looking  at 
some  of  the  standard  constructions  for  these  various  ele- 
ments it  will  be  interesting  to  examine  some  diagrams 
and  possible  general  arrangements.  In  Fig.  200  are 
shown  five  diagrams  of  stream  development,  prepared 
by  Professor  Mead,  lettered  A  to  E.  In  the  first  one, 


"£ 


FIG.  200 


250 


POWER 


A,  there  is  practically  no  head-race,  gates  and  wheels 
being  located  on  the  high  ground  above  the  dam,  and 
as  the  surface  slopes  away  rapidly  in  all  directions  a 
tail-race  is  excavated.  In  position  B,  the  land  is  all 
high,  so  that  instead  of  excavating  to  the  depth  re- 
quired for  a  tail-race  there  is  instead  a  head-race  ex- 
cavated, and  the  wheels  are 
located  on  the  steep  bank, 
discharging  directly  into  the 
stream.  The  land  sloping 
rather  abruptly  from  the  bank 
necessitates  a  construction  as 
shown  at  (7,  where  the  wheels 
are  located  in  a  down-stream 
extension  of  the  dam  itself,  or 
that  shown  at  D,  which  is 
practically  the  same  thing. 
In  diagram  E  the  land  is  so 
located  as  to  permit  of  the 
easy  construction  of  a  long 
head-race  parallel  to  the 
down-stream  part  of  the  river, 
and  between  this  head-race 
and  the  lower  banks  of  the 
river  many  wheels  are  located.  This  is  really  a  diagram 
of  the  old-fashioned  canal  development  arrangement. 
Bends  in  streams  are  often  favorable  points  to  develop, 
especially  when  the  bend  is  sharp.  Three  such 
possible  arrangements  are  shown  in  Fig.  201,  differing 
only  in  the  contour  of  the  location  of  the  land.  In 
the  upper  diagram  the  land  is  high  but  comparatively 
level  for  about  half  way.  It  then  rises  high  so  that 


FIG.  201 


WATER-POWER  SYSTEMS 


251 


a  head-race  is  economical  for  half  the  distance,  after 
which  a  tunnel  and  shaft  are  constructed  to  reach 
the  tail-race.  In  the  second  diagram  the  land  is  high 
for  nearly  the  whole  distance,  and  then  slopes  down 
to  the  water,  so  that  a  head-race  would  be  con- 
structed the  whole  way  and  the  wheels  be  located 
on  the  down-stream 
bank.  In  the  third 
diagram  the  land  is 
high  for  only  a  short 
distance.  It  then  slopes 
down  rapidly  and  is  low 
for  all  the  rest  of  the 
distance.  In  this  case 
the  wheels  are  located 
next  the  dam  and  dis- 
charge into  a  tail-race, 
excavated  across  the 
rest  of  the  point. 

Wheels  may  also  be 
located  in  a  variety  of 
ways  with  respect  to 
the  dam  itself,  or  to 
the  low,  pipe-line,  pen- 
stock, and  tail-water,  as 
shown  in  Figs.  202  and  203,  also  prepared  by  Professor 
Mead.  The  first  of  these  arrangements,  that  shown  at 
A,  is  that  of  a  vertical  shaft  turbine,  the  inlet  orifices  of 
which  are  incased  and  submerged  in  the  shallow  high- 
level  water,  the  discharge  water  passing  through  a  casing 
submerged  in  the  tail-water.  This  is  a  typical  arrange- 
ment for  a  very  low  head,  to  utilize  every  inch  of  height 


FIG.  202 


252 


POWER 


of  the  downward  projecting  tube,  and  is  called  a  draft 
tube,  as  it  acts  much  the  same  as  a  suction.  At  posi- 
tion B  is  shown  the  same  arrangement  except  for  high 
heads,  in  which  case  the  water  is  brought  to  the  wheel  by 
a  pipe  and  the  upper  part  is  surrounded  by  a  casing. 

Three  wheels  on  one 
shaft  of  the  open  inlet 
submerged  character  are 
shown  at  C,  with  two 
discharging  draft  tubes. 
Two  wheels  on  one  shaft 
with  single  discharge 
draft  tube  are  shown  at 
D.  In  both  cases  the 
shafts  are  vertical.  Two 
cases  of  horizontal  tur- 
bine shafts  with  exposed 
inlet  submerged  are 
shown  at  E  and  F. 
In  the  former  case  the 
whole  wheel  is  under 
the  water  and  in  the 


FIG.  203 


latter 
inlet, 
tubes. 


case    only    the 
Both  have  draft 


Referring  to  Fig.  203,  there  are  shown  six  arrange- 
ments of  horizontal  shaft  turbines,  in  the  first  of  which 
the  whole  machine  is  submerged  and  the  draft  tubes 
are  constructed  of  concrete.  In  B  the  wheel  is  inclosed 
and  rests  on  the  power  plant  floor,  and  is  supplied 
with  high-pressure  water  through  a  pipe,  but  discharges 
through  a  masonry  draft  tube  as  in  the  former  case. 


WATER-POWER  SYSTEMS 


253 


In  the  next  two  cases,  C  and  D,  horizontal  turbines 
completely  incased  receive  water  under  pressure 
through  pipe-lines,  and  discharge  through  draft  tubes 
in  the  tail-water.  In  the  former  case,  the  draft  tube 
is  of  metal,  and  in  the  latter  built  in  the  masonry.  The 
same  construction  as  that  shown  in  D  is  used  at  E, 


FIG.  204 

except  that  the  two  turbines  are  supplied  from  a  single 
pipe-line  in  opposite  directions,  discharging  through 
two  draft  tubes ;  while  at  F  the  construction  is  espec- 
ially adapted  to  low-head  working ;  the  two  turbines 
are  without  any  casing  for  their  inlets  and  are,  therefore, 
submerged,  while  a  common  discharge  leads  to  a  draft 
tube  on  the  lower  level. 


254 


POWER 


FIG.  205 


Returning  now  to  some  of  the  typical  constructions 

of  the  water  conduit  systems,  there  are  shown  in  Fig. 

204  a  small  fore- 
bay,  waste  dam, 
and  canal  inlet 
gate.  Near  the 
intake  of  the 
forebay  there 
will  be  located 
some  sort  of 
screen  to  keep 
out  logs  and 
floating  ice. 
This  illustrates 
the  intake  of 

the  Puget  Sound  Power  Co.  on  the  Puyallup  River. 

The  waste  dam  is  200  feet  long,  and  the  intake  62  feet 

wide  in  the  river  bank.     Water  entering  this  forebay 

and  canal  is  con- 
ducted about 

10  miles,  finally 

drops  872  feet, 

and  develops 

10,000h.p.  The 

canal    is    only 

8  feet  wide  and 

5    feet    deep. 

An  example  of 

head-gate     ar-  FIG  206 

rangement    for 

a  comparatively  small-sized  plant  is  shown  in  Fig.  205, 

and  represents  the  outlet  at  the  Great  Jezero  Lake 


WATER-POWER   SYSTEMS 


255 


in  Europe.  The  water  flowing  through  these  gates 
ultimately  develops  9000  h.  p.  A  still  larger  gate  is 
shown  in  Fig. 
206,  through 
which  are  led 
the  waters  of 
Lake  Superior, 
which  has  an 
area  of  30,000 
square  miles, 
escaping  natur- 
ally through  the 
Sault  Rapids, 
some  of  which, 
however,  has 
been  diverted 

through  this  canal  for  the  generation  of  about  60,000 
h.  p.  under  a  head  of  about  16  feet  by  submerged  wheels 
which  are  shown  in  Fig.  207.  Just  before  reaching  the 


FlG  2or 


FIG.  208 


wheels,  the   canal   expands   into   a  forebay  1400  feet 
wide,  at  the  end  of  which  is  located  on  one  side  the  power 


256 


POWER 


house,  and  on  the  other  the  spillway.     The  complete 
power  house  is  shown  in  Fig,  208,  and  the  ice-racks 


FIG.  209 


in  Fig.  209.  A  somewhat  more  elaborate  arrangement 
for  controlling  the  water  is  that  used  by  the  Ontario 
Power  Co.  at  Niagara  Falls,  shown  in  Fig.  210.  This 


FIG.  210 


is   a   beautifully   executed   hanging   wall   of   masonry 
under  which  the  water  must  flow. 


WATER-POWER"  SYSTEMS 


257 


These  few  illustrations  will  serve  to  show  the  variation 
in  structure  of  head  works,  including  forebays,  gates, 

etc.;  but  before    , 

the  water,  the 
diversion  of 
which  is  started 
at  the  head 
works,  can  be- 
come available 
it  must  be  con- 
ducted some 
distance.  This 
requirement  is 
most  commonly 

.     J  FIG.  211 

carried  out  first 

by  canals  and  later  by  pipes.     A  common  earth  canal 

is  shown  in  Fig.  211.     A  crude  sort  of  conduit  or  flume 


FIG.  212 


258 


POWER 


made  of  wooden  boards 
is  often  used,  and  by 
it  water  may  be  car- 
ried across  depressed 
points  on  bridges,  such 
as  shown  in  Fig.  212, 
a  section  of  the  wooden 
flume  of  the  San  Joa- 
quin  Co.,  already  re- 
ferred to.  A  more 
elaborate  and  expen- 
sive construction  is 
illustrated  in  Fig.  213, 
which  shows  a  concrete 
canal  issuing  from  a 
rock  tunnel,  bored 
through  the  mountain, 
and  forming  part  of 
the  Bosnia  develop- 
ment. 

An  elaborate  masonry  viaduct  is  illustrated  in  Fig. 
214,  forming  part  of  the  Tivoli  development,  previously 
illustrated  by  a 
general  view. 
This  latter  case 
is  a  good  ex- 
ample of  the 
most  expensive 
type  of  struc- 
ture, in  striking 
contrast  to  the 
tail-race  of  the  FIG.  214 


FIG.  213 


WATER-POWER  SYSTEMS 


259 


FIG.  215 


Susquehanna  River  development  at  McCall's  Ferry, 
shown  in  Fig.  215,  which  is  roughly  blasted  and 
left  unfinished. 
From  the 
forebay  or 
head-race  pipe- 
lines are  run  to 
the  lower  level, 
and  in  Fig.  216 
are  shown  three 
pipe-lines  under 
construction, 
connecting  with 
the  end  of  a 
canal  coming 
out  of  the 

woods.     Through  these  pipes  will  flow  water  to  develop 
some  5000  h.  p.,  involving  part  of  the  development  of 

Lakes  Joux  and 
Brenets  in 
Switzerland. 

Where  there 
is  a  dam  on  a 
stream,  as  has 
already  been 
noted,  it  is  pos- 
sible to  sub- 
merge wheels  in 
the  dam,  and  to 
illustrate  this 
point  there  are  presented  two  pictures  of  the  develop- 
ment at  Lowell,  Kansas,  on  the  Spring  River.  In 


FIG.  216 


260 


POWER 


the  first,  Fig.  217,  are  shown  some  cross-sections 
of  the  dam  at  various  points  and  in  different  direc- 
tions. Section  marked  AB  shows  controlling  gate, 


FIG.  217 

which  is  of  radial  form.  CD  shows  power  house 
built  inside  the  dam;;  section  EF  shows  a  turbine  lo- 
cated in  the  head-water  with  its  draft  tube  extending 
into  the  tail-water.  The  long  picture  at  the  bottom 
is  a  longitudinal  section  of  the  dam,  showing  the  loca- 
tion of  eight  wheels,  the  power  house,  and  the  controlling 


FIG.  218 


gates  for  regulating  the  head.     A  photograph  of  the 
dam  in  cross-section  is  shown  in  Fig.  218  from  the  down- 


WATER-POWER  SYSTEMS 


261 


stream  side ;  the  arches  just  appearing  out  of  the 
water  are  the  discharges  from  the  turbines  located 
within  the  masonry  structure.  At  this  point  the  dam 
is  1250  feet  long,  and  there  is  a  spillway  half  a  mile  up- 
stream. The  dam  is  30  feet  high,  and  with  a  head  of 
34  feet  2400  h.  p.  is  developed.  In  some  localities 
where  the  head  is  not  very  great,  especially  in  the 
beginning  of  a  long  pipe-line,  the  pipe,  instead  of  being 
of  riveted  steel,  is  made  of  wooden  staves.  Such  a 
construction  is 
illustrated  in 
Fig.  219  and  is 
used  by  the 
Pioneer  Elec- 
trical Power 
Co.  of  Utah, 
which  trans- 
mits electrically 
to  Ogden  and 
Salt  Lake  City 
some  10,000 
h.  p.  developed 
under  a  head  of 

450  feet.  This  water  pipe-line  is  5  miles  long  and  made 
of  2-inch  Oregon  pine  held  together  by  f-inch  steel  bands, 
of  which  87,000  were  used.  When  the  drop  in  level  be- 
comes excessive,  the  water  pipe  is  replaced  by  steel  pipe 
running  to  the  lower  level.  At  the  end  of  such  a  pipe- 
line is  located  a  power  house,  just  above  the  tail-waters. 
The  discharge  water  from  the  wheels  may  enter  draft- 
tubes  submerged  in  the  tail-water,  which  case  requires 
the  reaction  type  of  wheel,  or  it  may  drop  off  the  cir- 


FIG.  219 


262 


POWER 


cumference  of  open  impulse  or  bucket-wheels  such 
as  are  used  for  high  heads.  The  power  house  of  such 
a  high-head  development,  located  just  above  the  tail- 


Tv 


FIG.  220 

water,  showing  the  discharge  of  such  bucket-wheels, 
is  shown  in  Fig.  220.  The  other  construction  just 
mentioned  is  used  in  the  Canadian-Niagara  Power 
House,  at  Niagara  Falls.  The  water  from  the  fore- 
bay  is  led  verti- 
cally downward 
through  pipes 
set  in  excavated 
shafts  cut  in  the 
rock.  Draft 
tubes  from  the 
turbines  extend 
downward  into 
a  rock  excava- 
tion, finally 
leading  to  the 
tail-water.  The 


FIG.  221 


electrical  ma- 
chinery is  carried  on  the  upper-level  end  of  long  shafts. 
In  this  power  house  the  units  are  each  12,000  h.  p. 


WATER-POWER  SYSTEMS 


263 


maximum.  Five  are  installed,  and  there  will  be  ulti- 
mately six  more,  which  will  make  the  capacity  some- 
thing over  100,000  h.  p.  for  the  station  under  a  head  of 
135  feet. 

Another  arrangement  somewhat  similar  in  character 
and  also  in  use  at  Niagara  is  shown  in  Fig.  22 1 .     Here  the 


pipe  drops  from  the  forebay  vertically  for  a  distance 
and  then  inclines,  entering  the  power  house.  The 
construction  of  the  power  house  at  McCall's  Ferry  is 
shown  in  Fig.  222  in  cross-section,  indicating  that  no 
pipe-lines  at  all  are  used,  but  that  the  water  from  above 
the  dam  enters  through  head-gates  and  passes  through 
a  concrete  water  conduit,  reaching  double  wheels  and 
discharging  through  two  draft  tubes  to  the  tail-water. 
The  method  of  construction  of  these  concrete  draft 


264 


POWER 


tubes  is  shown  in  Fig.  223  with  part  of  the  dam  visible 
in  the  distance. 

From  what  has  been  said  it  can  readily  be  under- 
stood why  the  cost  of  water-power  is  so  variable  a 
quantity,  dependent  as  it  is  on  the  cost  of  development, 
which  is  seldom  twice  the  same.  Water-power  may 


be  the  cheapest  or  the  most  expensive.  When  water- 
power  cost  per  horse-power  hour  exceeds  that  of  fuel- 
burning  systems,  steam,  gas,  or  oil,  the  development 
is  not  warranted,  so  that  a  knowledge  of  the  cost  of 
power  by  these  fuel-burning  systems  for  the  particular 
locality  in  question  must  be  known  with  reasonable 
certainty  before  undertaking  any  water-power  develop- 


WATER-POWER  SYSTEMS  265 

ment.  Here  again  is  an  illustration  of  the  controlling 
influence  of  true  economy  on  the  engineering  methods 
to  be  employed  in  obtaining  power,  for  no  matter  how 
clever  and  ingenious  a  new  scheme,  it  is  warranted 
only  when  the  cost  of  the  service  to  be  rendered  is 
reduced  thereby. 


VIII 

SOCIAL   AND    ECONOMIC    CONSEQUENCES   OF   THE 
SUBSTITUTION    OF    POWER   FOR   HAND    LABOR 

POWER  is  seldom  useful  at  the  point  where  it  is  gen- 
erated, because  it  is  never  generated  for  its  own  sake, 
but  as  a  means  of  driving  machines  to  make  or  do 
something.  These  machines  must  necessarily  be  scat- 
tered more  or  less,  distributed  throughout  the  different 
floors  of  one  building,  or  located  in  each  of  a  number 
of  buildings  forming  part  of  the  same  establishment. 
In  fact,  one  power-generating  system  may  supply 
motive  power  to  the  machines  of  shops,  factories,  or 
railways  extending  over  hundreds  of  miles  of  country. 
The  object  is  to  drive  these  machines  and  drive  them 
as  economically  as  possible,  and  as  there  is  no  other 
reason  for  utilizing  nature's  energy,  without  machines 
to  drive  or  work  to  be  done  there  would  be  no  power 
systems.  From  the  commercial  or  industrial  stand- 
point the  power-generating  equipment  cannot  be  con- 
sidered by  itself,  but  only  in  association  with  some 
means  of  transmitting  the  power  from  that  place  where 
it  is  most  convenient  to  generate  it  to  that  place  where 
it  is  most  convenient  to  use  it.  These  power  trans- 
mission systems  take  a  great  variety  of  form,  but  may 
be  grouped  into  three  classes  for  the  purpose  of  review. 
The  first  will  include  direct  push  or  pull  by  mechanical 
elements ;  the  second  push  by  fluids  under  pressure 

266 


ECONOMIC   CONSEQUENCES  267 

with  or  without  expansion;  and  the  third  all  systems 
not  dependent  on  push  or  pull,  but  involving  a  trans- 
formation of  energy  from  a  form  not  easily  transmitted 
to  another  that  is.  When  the  distance  is  short,  the  direct 
push  of  the  teeth  of  wheels  or  gearing  may  be  used. 
At  a  little  greater  distance  between  driving  and  driven 
points  chains  running  on  toothed  wheels,  or  belts  of 
leather,  canvas,  or  steel,  running  on  smooth  wheels 
or  pulleys,  will  transmit  a  force  by  a  direct  pull  from 
the  circumference  of  the  driving  to  that  of  the  driven 
wheel.  In  these  cases,  however,  the  two  shafts  must 
be  at  not  too  great  distances.  Still  greater  distance 
between  driven  and  driving  shafts,  more  especially 
when  they  are  not  in  line,  or  where  the  transmission 
must  take  place  around  corners  of  buildings,  has  led 
to  the  substitution  of  ropes  running  in  grooved  wheels, 
constituting  the  rope  drive,  and  available  for  distances 
approximating  a  thousand  feet.  Gears,  chains,  belts, 
and  ropes  are  all  means  of  transmitting  power  from 
one  rotating  shaft  to  another  through  short  distances 
by  the  actual  transmission  of  a  force  by  push  or  pull 
at  some  properly  designed  part.  When  the  distances 
become  greater  than  it  is  safe  to  run  ropes,  then  the 
second  system  becomes  available  by  substituting  the 
pressure  push  of  fluids  in  pipes.  When  the  fluid  is 
non-compressible,  such  as  water,  there  is  no  further 
action  than  by  the  push,  but  the  use  of  air  permits  of 
additional  work  by  expansion.  If  an  engine  be  ar- 
ranged to  drive  a  pump,  all  its  energy  may  be  consumed 
in  pushing  water  against  a  certain  pressure  and  at  a 
certain  rate  through  pipes  that  may  be  of  any  size  or 
shape  or  length;  and  allowing  for  a  loss  in  pressure  by 


268  POWER 

friction  through  these  pipes,  the  water  may  exert  a 
corresponding  push  on  any  point  of  the  hydraulic  main 
and  be  there  used  to  operate  the  pistons  of  hydraulic 
engines.  Thus,  by  the  addition  to  the  engine  of  a 
pump,  an  hydraulic  motor,  and  a  water-pipe  connecting 
them,  the  engine  power  may  be  transmitted  almost 
any  distance  and  in  any  direction.  Such  an  hydraulic 
system  of  transmission  is  in  use  in  the  city  of  London, 
where  there  are  high-pressure  water-pipes  running 
through  the  streets,  supplied  from  a  central  station, 
and  delivering  water  to  hydraulic  elevators  and  motors. 
Of  course,  the  farther  the  water  is  transmitted  the 
greater  will  be  the  cost  of  pipe  and  the  greater  will  be 
the  loss  in  energy  by  friction  and  leakage;  so  that  at 
some  distance  the  cost  of  power,  which  is  continually 
increasing  each  foot  from  the  engine,  will  become 
greater  than  the  cost  to  generate  directly  by  a  com- 
peting system,  and  there  the  value  of  the  transmission 
system  ceases.  If,  instead  of  the  pump,  an  air  com- 
pressor be  driven  by  the  main  engine,  the  compressed 
air  delivered  to  pipes  may  be  made  to  flow  through 
the  piping  system  to  any  distance  desired,  and  from 
any  point  it  may  enter  a  compressed  air-engine,  similar 
in  all  respects  to  a  steam-engine,  and  there  do  work 
by  direct  push  and  by  its  expansion  in  addition.  As 
already  explained,  the  steam-engine  does  work  most 
economically  when  a  little  bit  of  high-pressure  fluid  is 
admitted  to  a  cylinder,  cut  off,  and  the  isolated  charge 
expanded  to  the  terminal  pressure.  Substituting  air 
for  steam,  the  action  would  be  the  same.  As  a  conse- 
quence, each  cubic  foot  of  high-pressure  air  can  do  ever 
so  much  more  work  than  a  cubic  foot  of  water  at  the 


ECONOMIC  CONSEQUENCES  269 

same  pressure,  and  as  a  consequence,  a  pipe  of  a  given 
size  can  transmit  more  power  in  the  form  of  compressed 
air  than  in  the  form  of  water.  Compressed  air  trans- 
mission systems  are  very  much  more  common  because 
they  may  be  made  more  economical  than  hydraulic 
systems  so  far  as  the  pipe-line  is  concerned.  They 
are  used  extensively  about  shops  and  mines,  the  air 
being  pumped  into  the  mine  to  operate  drills,  hoists, 
and  sometimes  pumps  as  well,  the  exhaust  from  the 
machine  also  helping  to  keep  the  air  pure  for  breathing 
and  assisting  the  ventilation.  In  the  streets  of  Paris 
there  are  laid  compressed  air  mains  for  transmitting 
power  in  this  form  from  a  central  station  to  users 
scattered  throughout  the  town.  Even  the  compressed 
air  system,  which  is  better  adapted  to  long  distances 
than  the  others  examined,  is  limited  to  a  few  miles  so 
far  as  economical  transmission  of  power  is  concerned. 
When  really  long  distances  are  to  be  covered,  then  the 
third  method  noted,  that  of  change  of  energy  form,  is 
still  available.  In  fact,  some  of  the  systems  of  this 
class  are  found  to  be  even  better  for  the  short  distances 
than  those  systems  that  are  limited  to  the  short  distance. 
There  are  two  systems  in  this  class:  one  transforms 
shaft  power  into  electric  energy  which  flows  over  wires, 
and  the  other  transforms  the  fuel  into  the  gaseous  form 
and  transmits  it  through  pipes  ;  this  latter  is  as  yet  not 
much  used. 

The  most  commonly  used  power  transmission  system 
to-day  is  the  electric,  and  this  is  employed  for  all  dis- 
tances up  to  and  even  exceeding  one  hundred  miles.  In 
many  cases  it  is  found  economical  even  within  the  limits 
of  a  single  factory  building  to  transform  the  shaft  power 


270  POWER 

directly  into  electric  energy,  transmitting  this  over 
wires  to  electric  motors  located  directly  on  each  machine 
requiring  power.  Of  course,  each  transformation  and 
each  foot  of  transmission  involves  a  loss  of  energy,  and 
the  studying  out  of  the  conditions  fixing  the  economical 
limit  of  distance  for  any  system  is  one  of  the  nice  and 
difficult  engineering  problems  of  the  day. 

The  fundamental  ideas  underlying  the  electric  trans- 
mission of  power  are  very  simple,  but  the  details  of 
most  economic  execution  are  extremely  complicated. 
Nearly  every  one  knows  what  a  magnet  is,  and  some- 
thing of  the  flow  of  electric  current  over  wires  to  ring 
bells  and  operate  telegraph,  telephone,  and  electric  lights; 
but  not  so  many  know  of  the  relation  between  a  magnet 
and  an  electric  current  flowing  on  wires.  The  dis- 
covery of  this  relation  was  one  of  the  greatest  in  point 
of  scientific  and  commercial  value  that  the  world  has 
ever  seen.  Faraday  found,  about  the  year  1832,  that 
when  a  wire  is  moved  in  the  neighborhood  of  a  magnet 
an  electric  current  will  flow  through  the  wire  and  it  will 
take  some  pushing  to  accomplish  the  movement.  Now 
dynamos  or  electric  generators  are  nothing  more  than 
well-designed  magnets,  past  which  many  wires  can 
be  pushed  mechanically  and  in  an  orderly  manner. 
Each  individual  wire  as  it  passes  the  magnet  has  a 
current  of  electricity  set  up  in  it,  starting  from  zero 
as  it  approaches,  later  rising  to  a  maximum,  and  finally 
falling  to  zero  again  as  it  leaves  the  magnet.  Many 
wires  passing  rapidly  in  succession  may  be  made,  by 
suitable  mechanism,  to  contribute  each  its  share  of 
electric  current  and  all  these  small  currents  added 
up,  or  accumulated  in  one,  constitute  the  output 


ECONOMIC   CONSEQUENCES  271 

of  the  generator.  The  way  in  which  the  adding  up 
is  done  differs  in  different  types  of  generators  and  con- 
stitutes the  difference  between  them.  Now,  this  same 
current  which  was  generated  by  driving  wires  across 
the  faces  of  magnets  will,  if  led  to  one  or  more  wires 
near  the  face  of  other  magnets,  result  in  the  reverse 
operation.  As  soon  as  the  current  flows  through  one 
wire  the  wire  will  push  itself  with  respect  to  the  magnet, 
and  many  wires  fastened  on  a  drum  will  cause  that 
drum  to  rotate.  This  is  the  basal  principle  of  the 
electric  motor,  which  like  the  dynamo  consists  of  bundles 
of  wires  carried  on  drums,  disks,  or  wheels  of  suitable 
sort,  and  a  system  of  magnets.  In  the  case  of  the 
generator  the  wires  are  pushed  past  the  magnet  by  the 
engine  power  and  a  current  generated.  In  the  case 
of  the  motor  the  current  is  led  through  the  wires  and 
a  push  results,  which  may  be  made  continuous  rotary 
motion.  It  is  somewhat  curious  that  this  double  or 
reciprocal  action  between  the  wires  and  the  magnets 
was  not  recognized  at  the  same  time.  While  the  prin- 
ciple of  current  generation  was  discovered  in  1832,  it 
was  not  until  1873,  or  forty-one  years  later,  that  the 
reciprocal  action  was  found,  making  it  possible  to  oper- 
ate a  motor  from  a  generator  any  distance  away,  and 
through  the  double  transformation  of  energy  transmit 
the  power  of  the  prime  mover  or  engine  proper.  Long 
distance  transmission  was  accompanied  by  great  losses 
with  the  sort  of  electric  current  first  generated,  and  it 
was  not  until  the  discovery  that  a  current  of  very  high 
voltage  or  pressure  could  be  transmitted  with  much 
less  loss,  that  economical  long  distance  transmission 
became  possible.  The  economic  and  safe  application 


272  POWER 

of  this  idea  involved  the  design  of  additional  apparatus, 
called  transformers,  for  changing  the  pressure  of  a  cur- 
rent, or  even  one  kind  of  current  into  another,  so  that  a 
generator  might  be  built  to  make  any  kind  of  current 
at  any  convenient  pressure  which  could  be  transformed 
to  high  pressure  for  transmission,  and  near  the  motor 
be  again  changed  to  a  pressure  or  kind  adapted  to  the 
most  convenient  or  suitable  kind  of  electric  motor. 
The  first  practical  high  tension  long  distance  trans- 
mission system  of  this  kind  was  not  installed  until  1893, 
only  seventeen  years  ago,  at  Great  Barrington,  Massa- 
chusetts, whereas  to-day  it  would  be  practically  im- 
possible to  make  a  list  of  the  electric  transmission 
installations,  so  numerous  have  they  become. 

When  gas  is  generated  in  gas  producers,  as  explained, 
it  is  possible  to  conduct  that  gas  through  pipes  to  en- 
gines located  at  a  distance,  so  that  the  transmission  of 
gas  in  pipes  to  gas-engines  really  constitutes  a  power- 
transmission  system,  the  most  recent  of  the  methods 
now  under  consideration.  It  is  so  far  but  little  used  in 
this  country,  although  it  has  been  applied  to  factories 
in  Germany,  where  a  gas  producer  located  at  a  most 
convenient  point  for  the  receipt  of  coal  makes  gas  for 
transmission  to  ten  or  a  dozen  factory  buildings  scat- 
tered over  many  acres,  each  with  its  own  gas-engine ; 
the  same  gas  is  also  available  for  the  operation  of  in- 
dustrial gas  furnaces  and  with  suitable  mantles  the 
generation  of  factory  light. 

We  have  seen  that  there  are  three  systems  of  power 
generation,  the  steam,  gas,  and  water  systems,  and  a 
great  variety  of  means  of  transmission;  so  that  the 
decision  as  to  which  form  of  natural  energy  to  use, 


ECONOMIC  CONSEQUENCES  273 

whether  fuel  or  water,  and  by  which  system  to  trans- 
form it  into  work  and  to  transmit  the  energy  developed 
to  the  machines  requiring  it,  is  a  problem  of  great  com- 
plexity having  two  distinct  phases,  one  strictly  sci- 
entific and  the  other  commercial,  the  two  together 
constituting  one  branch  of  engineering  practice,  and  con- 
stituting one  of  the  first  and  most  fundamental  steps 
in  the  carrying  out  of  any  industrial  problem  of  manu- 
facture or  transportation.  That  system  of  generation, 
transmission,  and  application  of  power  to  any  machine 
requiring  power  that  is  best  for  the  particular  case  is 
the  one  that  will  perform  the  required  duty  for  the 
lowest  cost;  and  in  the  determination  of  the  best,  general 
rules  are  of  comparatively  little  use.  Each  case  must 
be  studied  by  suitably  qualified  experts,  and  all  the 
data  collected  on  the  different  possible  and  satisfactory 
ways,  with  the  cost  of  each,  must  be  compared,  before 
a  judgment  can  be  reached;  and  it  seldom  happens  that 
all  the  systems  or  methods  are  equally  suitable  or  that 
the  most  suitable  is  cheapest.  The  judgment  must, 
therefore,  involve  a  weighing  of  cost  against  relative 
suitability.  For  example,  cars  and  trains  may  be  moved 
by  steam  locomotives  or  by  electric  motors  supplied 
from  a  central  station.  It  has  been  found  that  in  the 
streets  of  cities  the  steam  system  cannot  compete  either 
in  cost  or  suitability  of  service  with  the  electric,  while 
on  transcontinental  or  trunk  lines  the  steam  is  so  far 
superior  in  point  of  cost,  though  the  electric  would  be 
equally  suitable.  Cases  intermediate  between  the 
congested  and  dense  city  traffic  and  the  long  haul  with 
light  traffic  present  a  most  difficult  problem  of  the 
weighing  of  suitability  and  cost,  and  one  that  is  to-day 


274  POWER 

agitating  practically  every  railroad  the  world  over, 
but  without  as  yet  any  generally  accepted  solution. 
Similarly,  the  driving  of  machines  in  a  factory  offers 
a  parallel  controversial  case,  for  they  may  be  driven 
by  belts  from  a  central  plant  or  by  electric  motors 
supplied  by  engine-driven  electric  generators.  In 
some  cases  the  electric  system  has  proved  its  unques- 
tioned superiority,  in  others  the  belts  are  better;  but 
in  the  great  majority  of  cases  there  is  a  lack  of  concerted 
opinion,  even  though  relative  costs  and  suitability 
have  been  much  studied  and  the  data  tabulated  and 
published. 

With  regard  to  generation  itself  the  situation  is 
equally  complex ;  in  most  cases  there  may  be  just 
controversy  and  difference  of  opinion,  while  in  others 
the  proper  course  to  pursue  is  clear.  For  example, 
when  the  work  to  be  done  is  continuous  and  the  average 
load  near  the  maximum  power  capacity  of  the  plant, 
the  fuel  and  labor  costs  are  high  in  proportion  to  in- 
vestment charges,  and  very  expensive  machinery  is 
warranted  if  it  can  save  ever  so  little  in  the  fuel  charges. 
This  is  the  case  with  most  municipal  water-supply 
pumping  stations.  On  the  contrary,  if  the  average 
power  demand  is  very  small  in  proportion  to  the  maxi- 
mum, then  for  a  large  part  of  the  time  the  machinery 
is  idle,  and  the  investment  charge  per  unit  of  power 
generated  becomes  high  in  proportion  to  the  fuel,  and 
only  cheap  machinery  is  warranted  even  if  the  fuel 
cost  is  high.  Such  is  the  case  with  farm  engines  which 
may  work  at  full  load  only  a  month  or  two  in  the  year. 
Again,  if  fuel  is  very  cheap,  as  at  the  mines,  where  it 
seldom  exceeds  eighty  cents  per  ton,  it  would  not  be 


ECONOMIC   CONSEQUENCES  275 

good  practice  to  use  expensive  equipment  to  save  fuel; 
while  in  countries  like  Mexico  and  South  America, 
where  coal  often  reaches  $12  per  ton,  almost  any 
expense  in  machinery  would  be  warranted  to  make  the 
coal  go  as  far  as  possible. 

It  can  be  said  that  there  is  only  one  best  way  for 
each  case,  but  an  almost  infinite  variety  of  cases,  and 
the  amount  of  time  and  study  to  be  expended  in  finding 
the  best  that  may  be  justly  warranted  must  be  based 
on  the  saving  that  might  be  effected  by  selecting  the 
best  over  the  worst;  for  if  a  preliminary  examination 
showed  four  different  systems  to  be  equally  suitable 
and  nearly  equal  in  cost,  it  would  not  pay  to  bother 
much  with  working  out  the  exact  details  of  each,  when 
any  one  would  do.  The  most  elaborate  study  is  war- 
ranted only  when  the  possible  ranges  of  cost  are  great, 
or,  and  most  often,  when  the  cheapest  is  not  as  equally 
suitable  as  the  most  costly. 

After  all,  we  are  all  not  so  much  concerned  with  the 
ways  in  which  power  may  be  generated  for  its  own  sake, 
or  even  the  relative  value  of  the  ways  it  may  be  trans- 
mitted and  applied  to  the  machinery  of  manufacture 
and  transportation,  as  we  are  with  the  bigger  industrial 
problem  of  daily  supply  of  the  world  with  the  means 
for  comfortable  living.  From  what  has  been  said  con- 
cerning the  complexity  of  the  power  problem,  it  may 
be  easily  inferred  that  this  larger  question,  by  reason 
of  the  greater  number  of  things  that  enter  into  it,  is 
ever  so  much  more  complex  and  must  be  approached 
with  great  caution  if  one  would  avoid  drawing  unwar- 
ranted conclusions.  However  complex  or  big  a  ques- 
tion ma}^  seem,  it  can  by  patient  study  and  analysis 


276  POWER 

be  resolved  into  simple  terms,  and  guiding  principles 
be  evolved  that  are  useful.  While,  to  be  sure,  there 
will  always  be  certain  questions  left  ever  unsolved, 
and  hence  of  controversial  nature,  yet  the  fact  that 
out  of  the  chaos  some  order  has  been  evolved  proves 
the  effort  is  worth  while  and  leads  to  a  belief  that  con- 
tinued study  along  sound  scientific  and  logical  lines  will 
finally  resolve  the  rest. 

It  has  been  said  that  by  the  introduction  of  power- 
driven  machinery  the  modes  of  life,  habits,  comforts, 
and  pleasures  of  the  great  mass  of  the  people  were  greatly 
changed;  so  much  so  as  to  lead  historians  to  charac- 
terize the  movement  as  the  industrial  revolution, 
meaning  thereby  not  only  that  industrial  methods 
were  revolutionized,  but  the  whole  world,  by  means 
of  and  as  a  result  of  these  industrial  changes,  all  of 
which  started  with  the  use  of  power-driven  machinery 
when  James  Watt  applied  his  steam-engine  to  the 
driving  of-  textile  mills  in  England  one  hundred  and 
sixty  years  ago. 

This  industrial  change  was  briefly  reviewed  in  the 
first  lecture  of  this  series;  the  magnitude  of  the  modern 
industries  which  did  not  exist  before  the  time  noted 
was  pointed  out,  as  well  as  the  ever  increasing  propor- 
tion of  the  population  directly  dependent  on  them 
for  wages  and  salaries;  the  equally  large  number  of 
traders  or  merchants  supplying  raw  material  and 
distributing  manufactured  products  of  ever  changing 
form  from  the  same  natural  substances  that  have  always 
existed  since  the  world  began;  the  absolute  dependence 
of  all  of  us  on  the  manufactures  and  the  transportation 
systems  for  all  that  we  need  and  much  that  we  do, 


ECONOMIC  CONSEQUENCES  277 

and  the  importance  to  all  of  at  least  trying  to  under- 
stand how  it  all  has  happened.  With  such  world 
questions  before  us,  why,  then,  has  so  much  time  been 
spent  in  discussing  the  construction  of  steam-boilers, 
gas  producers,  vaporizers,  engines,  turbines,  nozzles, 
and  valves,  and  in  studying  the  principles  of  gasifica- 
tion and  combustion  of  fuel,  generation  and  expansion 
of  steam,  or  the  flow  of  water,  when  instead  attention 
might  have  been  directed  to  the  more  popular  questions 
of  industrial  growth  itself,  its  effects  on  the  organiza- 
tion of  society,  the  creation  and  distribution  of  wealth, 
or  the  government  of  the  people  ?  Because  these  ques- 
tions, of  infinite  complexity  compared  to  the  economic 
generation  and  application  of  power  to  machines,  have 
been  much  discussed  by  economists,  sociologists,  his- 
torians, and  statesmen,  while  the  power  question, 
which  is  so  large  a  factor  and  so  strong  a  formative 
force,  has  never  been  presented  to  a  popular  audience ; 
and  finally,  but  by  no  means  least,  because  it  is  the 
finest  possible  example  of  the  value  of  patient,  logical, 
scientific  study,  in  resolving  complexity  into  com- 
parative simplicity,  yielding  to  exposition,  and  serving 
as  a  model  of  the  method  to  be  applied  to  the  apparently 
more  complex  and  larger  questions.  Place  before  the 
average  man  a  collection  of  all  the  standard  power- 
generating  machinery,  and  it  would  not  be  too  much 
to  say  that  he  would  at  once  admit  its  explanation  and 
creation  to  be  far  more  difficult  for  him  to  discuss  than 
a  question  of  politics,  government,  or  economics,  on 
all  of  which  he  has  some  well-defined  opinions,  and 
yet  all  of  these  are  far  more  difficult  to  solve  than  any 
machinery  problem ;  how  much  more  cautious,  then, 


278  POWER 

should  we  be  in  reaching  conclusions,  and  how  much 
more  needed  is  a  method  of  procedure  that  is  safe  and 
sane.  Who  could  have  foreseen  the  tremendous  effects 
of  studying  wheels,  cylinders,  rods,  and  chambers,  and 
the  designing  of  these  to  carry  out  the  physical  processes 
of  rendering  available  for  man's  use  nature's  energy 
to  change  into  useful  and  more  serviceable  forms  the 
substances  of  sea,  farm,  forest,  and  mine  ?  Probably 
no  one.  It  is  not  surprising,  then,  that  the  average 
man  has  a  feeling  that  there  is  no  connection  between 
his  needs  and  pleasures,  his  commercial  or  social  stand- 
ing, his  opinion  or  mode  of  thinking,  and  the  dirty 
shop,  the  hot  and  mysterious  engine  room,  the  laws  of 
thermodynamics  and  hydraulics,  and  their  application 
to  machine  structures,  or  any  other  part  of  the  problem 
of  power  generation  and  its  application  to  manufac- 
ture and  transportation.  Yet  there  is  a  twofold  con- 
nection, for  without  these  things  the  world  would  not 
be  what  it  is  to-day,  and  the  methods  and  principles 
involved  in  the  creation  of  the  machinery  have  re- 
vealed Nature  herself,  and  are  equally  applicable 
to  the  other  problems  that  seem  of  more  intimate  im- 
portance. No  man  can  afford  to  fail  to  inquire  into 
all  that  concerns  his  welfare,  more  especially  those 
things  that  may  serve  to  guide  his  thinking,  which  con- 
trols action;  yet  it  is  all  too  true  that  not  only  has  the 
study  of  industrial  development  and  its  effects  been 
neglected  by  the  public  in  general,  but  the  work  and 
methods  of  the  scientific  mechanical  engineer,  who  is 
responsible  for  it,  are  practically  unknown. 

So  far  attention  has  been  directed  mainly  to  the 
work  of  the  engineer  in  developing  the  machinery  of 


ECONOMIC   CONSEQUENCES  279 

power;  but  the  machinery  to  be  driven  is  of  equal, 
if  not  greater,  importance,  and  while  time  will  not 
permit  us  here  to  examine  the  principles  and  appa- 
ratus of  the  manufacture  of  all  the  articles  of  com- 
mon use,  it  would  be  decidedly  worth  while  to  do  so. 
Precisely  the  same  methods  are,  however,  applied 
as  have  been  reviewed  in  the  discussion  of  the 
power  machinery,  and  it  is  hoped  that  what  has 
been  said  will  serve  to  arouse  interest  enough  to 
induce  a  few  to  take  up  some  reading  on  this  phase 
of  the  subject. 

All  the  time  that  the  engineer  of  the  industries  has 
been  creating  or  applying  machinery  for  the  most 
economic  use  of  nature's  energy  and  of  the  common 
substances  used  in  manufacture,  he  has  had  to  meet 
constantly  the  parallel  problem  of  making  the  best  use 
of  the  effort  of  man  himself  in  the  production  of  results, 
for  results  are  obtained,  not  by  power  alone,  by  machin- 
ery alone,  by  men  alone,  but  by  all  working  together. 
It  is,  therefore,  just  as  much  the  duty  of  the  engineer, 
who  began  by  studying  nature's  substances  and  forces, 
to  study  also  the  forces  controlling  men,  so  that  each 
individual  may  contribute  the  best  that  is  in  him,  just 
as  in  the  case  of  an  engine  itself.  This  parallel  study 
of  the  most  economic  use  of  man's  own  efforts  has  been 
placed  on  a  scientific  basis  only  in  recent  years,  and 
from  present  indications  is  destined  to  receive  as  much 
painstaking  analysis  in  the  future  as  it  has  lacked  in 
the  past,  which  lack  was  the  cause  of  much  disorder, 
misery,  abuse,  and  social  unrest  in  the  early  days  of 
industrial  expansion.  With  a  brief,  but  necessarily 
hopelessly  inadequate,  review  of  some  of  these  social 


280  POWER 

and  economic  changes,  to  round  out  the  subject,  we 
shall  close  this  series. 

In  the  old  days,  and  by  the  old  days  we  shall  under- 
stand the  days  before  the  steam-engine  and  the  machine 
method  of  manufacturing  which  it  made  possible,  the 
people  could  be  divided  into  classes  somewhat  as  fol- 
lows. The  first  class  would  include  all  those  who 
produced  everything  they  needed,  and  this  would  be 
the  largest  class  of  all,  constituting  the  bulk  of  the  popu- 
lation, the  farmer  or  domestic  manufacturing  group. 
The  materials  for  food,  clothing,  housing,  heating, 
and  lighting  were  all  produced  on  the  spot  by  the  man 
and  his  family,  with  perhaps  a  few  helpers.  It  was 
unnecessary  to  buy  anything  except  the  luxuries,  and 
few  of  these  were  indulged  in  by  this  class.  Being 
independent  of  their  neighbors,  there  was  no  particular 
necessity  for  travel,  so  that  there  were  few  towns,  and 
these  were  small.  Occasional  gatherings  at  fairs  were 
held  largely  for  pleasure,  but  partly  for  trade,  which 
consisted  mostly  in  exchange  of  horses,  cows,  or  wool, 
or  whatever  one  man  had  in  excess  for  that  of  which  he 
was  a  little  short.  In  the  second  class  there  would  be 
grouped  those  people  who  produced  nothing  at  all,  - 
the  soldier,  policeman,  preacher,  and  government  officer. 
These  bought  everything  they  needed,  to  supply  which 
a  little  transportation  was  maintained,  carried  on  by 
wagons,  sailing  vessels,  or  canal-boats.  This  class 
constituted  the  principal  town  population,  together 
with  those  few  traders  who  served  as  middlemen  be- 
tween the  producer  and  the  non-producing  consumer. 
The  third  class  would  include  those  people  who  pro- 
duced some  of  the  things  they  needed  and  bought 


ECONOMIC   CONSEQUENCES  281 

the  rest,  such  as  he  who  set  up  a  few  hand-looms  in 
a  village  and  bought  wool,  making  cloth  for  himself 
and  selling  it  to  others.  In  some  cases  the  farmer 
would  also  be  included  in  this  class,  when,  for  example, 
he  bought  a  wagon  or  cloth.  The  fourth  class  would 
include  those  who  produced  all  the  time  for  others, 
but  made  practically  nothing  that  they  needed  them- 
selves, devoting  their  time  to  the  creation  of  things  for 
others,  which  they  sold  and  from  the  returns  of  which 
they  bought  what  they  needed.  This  would  include 
the  ship-builders,  who  never  sailed  a  ship  that  they 
built,  the  tailor,  who  spent  all  his  time  in  making 
clothes  for  other  people,  the  iron  maker,  carpenter, 
mason,  shoemaker,  jeweler,  and  the  armorer.  The 
size  of  this  class,  which  consisted  partly  of  wage-earners 
and  partly  of  master  workmen,  who  were  also  traders, 
was  comparatively  small,  being  limited  by  the  size  of 
the  class  that  could  afford  to  buy  their  services.  The 
really  large  class  was  the  farmer  or  agricultural  group. 

When  the  power-loom  and  spinning-machines  were 
produced  and  the  steam-engine  put  to  work  to  drive 
them,  the  whole  condition  of  affairs  changed;  and 
following  the  same  analysis  there  was  an  enormous 
increase  in  the  wage-earning  group,  the  last-mentioned 
producing  class,  with  a  corresponding  decrease  in  the 
farmer  or  domestic  manufacture  class.  More  and 
more  people  came  to  work  in  the  factory,  because  it 
could  produce  cloth  far  cheaper  than  it  could  be  made 
by  hand  spinning  and  hand-looms  in  isolated  homes 
in  the  country.  Every  such  factory  worker  became 
a  producer  of  goods  that  he  did  not  use  himself  except 
in  a  very  small  degree;  and  as  factories  increased  in 


282  POWER 

numbers  the  factory  system  displaced  the  domestic 
system  of  production  not  only  in  cloth,  but  in  all  things. 
This  continuously  producing  class  of  factory  workers, 
drawing  on  the  independent  farmer  class,  decreased 
the  number  of  self-contained  individual  families,  and 
thus  was  set  up  what  amounts  to  practically  a  new 
organization  of  society,  as  a  result  of  what  has  come 
to  be  known  as  the  factory  system.  The  concentration 
of  workers  around  a  factory  created  a  town  or  enlarged 
an  existing  town.  The  presence  of  many  workers 
stimulated  the  location  of  another  factory  there.  Thus 
factory  followed  factory,  town  population  continuously 
increased,  and  the  farm  population  decreased.  In  this 
way  is  the  growth  of  the  city  traced  to  the  factory  and 
back  to  the  steam-engine  or  power  plant  as  the  prune 
factor  in  its  creation.  This  same  concentration  of 
population  in  cities  producing  practically  anything 
that  was  needed  stimulated  a  corresponding  increase 
in  the  trading  class.  The  factory  worker  did  not  pro- 
duce his  food  any  more,  but  had  to  buy  it.  So  the 
grocery  store  and  butcher  shop  increased  in  numbers 
enormously,  and  being  located  in  the  cities  to  supply 
city  workers,  their  owners  and  clerks  in  turn  increased 
the  population  of  the  city  and  drew  still  more  from  the 
farms. 

All  farm  productions  as  well  as  those  of  the  mine  and 
the  sea  had  now  to  be  transported  to  these  cities  to 
feed  the  factory  workers  and  the  tradesmen  and  to 
keep  them  supplied.  Thus  was  transportation  stimu- 
lated, stimulated  to  a  degree  that  ultimately  demanded 
the  creation  of  the  locomotive  and  steamboat.  Trans- 
portation was  also  stimulated  in  another  direction, 


ECONOMIC   CONSEQUENCES  283 

for  not  only  were  the  food  and  other  necessities  for  the 
city  population  to  be  brought  from  a  distance,  but 
likewise  the  raw  materials  for  the  factory,  which  had 
a  capacity  in  a  short  time  far  exceeding  that  of  the  sur- 
rounding country  to  supply.  Ships  and  railroads  were 
put  to  work  to  bring  these  raw  materials  from  all  over 
the  earth,  to  keep  the  factory  supplied,  and  it  was 
cheaper  to  do  this  than  to  continue  the  domestic  manu- 
facture near  the  place  where  the  raw  material  was  pro- 
duced. It  must  have  been  cheaper  or  it  never  would 
have  been  done.  Having  drawn  the  raw  material 
from  all  over  the  earth  to  the  factories  for  manufacture, 
there  was  necessary  a  reciprocal  transfer  or  transporta- 
tion system,  because  the  manufactured  article  was 
produced  in  quantities  exceeding  the  capacity  of  the 
immediately  surrounding  country  and  town  to  use. 
England  produced  cloth  for  the  whole  world,  as  well  as 
many  other  things,  for  it  was  in  England  that  these 
changes  took  place  originally  and  developed  most 
rapidly.  It  is  easy  to  see  by  such  analysis  as  this 
how  the  simple  act  of  driving  machines  by  engines  for 
the  doing  of  work  formerly  done  by  hand  created  the 
city,  increased  the  trading  class,  stimulated  transporta- 
tion to  a  degree  only  satisfied  by  the  application  of  the 
same  steam-engine  that  created  the  factory,  and  the 
transportation  demand  to  the  movement  of  the  car 
or  boat. 

There  were  other  effects,  however,  as  important  and 
far-reaching  as  these,  and  necessary  accompaniments 
or  consequences.  This  transportation  to  and  from 
factories  and  all  parts  of  the  earth  was  the  beginning 
of  the  modern  world  commerce,  the  enormous  increase 


284  POWER 

in  the  class  of  wholesale  dealer  of  manufactured  com- 
modities and  raw  materials,  as  well  as  in  the  class  of 
retail  storekeeper  in  every  town  of  the  land,  to  supply 
that  which  the  factory  made  so  much  better  and  cheaper 
than  it  could  have  been  produced  before,  or  that  which 
the  factory  made  which  had  never  been  heard  of  before. 
To  buy  a  ship-load  of  raw  material,  transport  it  across 
the  ocean  in  ships  that  might  take  months  in  trans- 
porting, required  the  tying  up  of  large  sums  of  money, 
and  this  could  be  done  only  by  him  who  had  the  money. 
Similarly,  the  buying  of  a  ship-load  of  manufactured 
goods  to  be  sent  from  England  to  China  likewise  re- 
quired capital,  for  during  all  the  period  between  pur- 
chase and  sale  a  large  sum  of  money  or  its  equivalent 
in  value  is  idle,  and  the  act  can  be  accomplished  only 
by  the  possession  of  capital.  The  manufacturer, 
between  the  time  of  purchase  of  raw  material  and  the 
time  of  sale  of  manufactured  product,  has  given  out 
money  for  which  there  is  no  return.  Not  only  has  he 
paid  out  money,  which  might  be  thus  tied  up  for  months 
or  even  years  in  the  material  itself,  but  he  must  con- 
tinually pay  workmen  through  this  whole  period  of 
time,  they  demanding  their  pay  every  day  or  every 
week  regularly.  There  is  likewise  required  capital 
sufficient  to  maintain  operation  between  the  period  of 
wholesale  purchase  of  manufactured  goods  and  their 
retail  sale.  Even  before  the  factory  can  be  started,  great 
buildings  must  be  erected  and  enormous  sums  of  money 
sunk  in  the  filling  of  them  with  machinery.  This 
likewise  required  capital.  No  one  could  manufacture 
and  no  one  could  carry  on  the  world's  commerce  who 
had  not  capital.  Now,  in  the  days  when  these  move- 


ECONOMIC  CONSEQUENCES  285 

ments  started,  there  was  practically  no  use  for  capital, 
that  is  to  say,  comparatively.  The  only  rich  people 
were  the  landowners  or  those  who  had  been  landowners, 
or  descended  from  them,  and  whose  accumulation  of 
wealth  had  been  derived  largely  from  farm  rentals.  The 
manufacturing  era  offered  to  those  who  had  capital 
an  outlet,  and  no  one  could  engage  in  the  business  who 
did  not  have  the  capital,  and  he  who  had  the  capital 
and  used  it  in  this  way  could  expect  returns  for  his 
money  and  make  a  profit  and  thus  accumulate  more. 
So  there  was  a  tendency  established,  continuing  to  our 
present  day,  toward  the  concentration  of  wealth, 
sometimes  described  as  the  "rise  of  capitalism,"  trace- 
able directly  to  the  use  of  power-driven  machinery 
more  than  any  other  single  thing.  It  frequently  hap- 
pened that  periods  of  hard  times  appeared.  The  farms 
did  not  yield  their  crops,  and  the  purchase  of  every- 
thing decreased.  The  new  manufacturer  produced 
standard  goods  far  in  advance  of  real  demand  or  without 
regard  to  any  known  demand,  contrary  to  the  old 
domestic  worker  who  made  a  shoe  only  when  somebody 
asked  for  it,  and  then  made  it  to  fit  a  particular  foot. 
These  periods  of  business  depression,  now  so  called, 
found  the  manufacturer  with  large  sums  of  money 
tied  up  in  unsold  goods,  which  had  been  made  up  only 
on  a  hope  that  they  could  be  sold,  but  which  he  was 
sure  he  could  sell  perhaps  the  next  year.  He,  therefore, 
did  not  want  to  stop  his  factory,  but  manufactured 
for  stock,  to  be  able  to  supply  the  retarded  demand 
when  it  came  and  to  keep  his  skilled  workmen  busy. 
He  might  decrease  the  output,  but  it  must  be  kept 
going.  He  must  pay  wages  all  this  time  to  his  work- 


286  POWER 

men,  so  he  had  to  borrow  money  on  the  goods  he  pos- 
sessed, as  security.  Thus  was  established  the  modern 
system  of  industrial  banking,  the  borrowing  and  loaning 
of  money  in  vast  sums  to  keep  industrial  enterprises 
going  between  periods  of  purchase  of  stock  and  sale 
of  product. 

The  factory  owner,  besides  being  a  buyer  of  raw 
materials  and  seller  of  manufactured  product  and 
owner  of  factory  with  its  machinery,  was  an  employer 
of  labor,  labor  of  all  sorts  from  the  most  unskilled  and 
ignorant  to  the  most  skilled  physically,  or  the  most 
highly  developed  mentally,  of  course,  in  different  pro- 
portions for  the  different  classes.  These  factory  workers 
constituted  a  large  class  of  the  community  and  were 
themselves  divided  into  classes.  There  was  a  man 
skilled  in  firing  boilers,  a  man  skilled  in  taking  care  of 
the  engines,  other  men  skilled  in  maintaining  the  ma- 
chines and  repairing  them,  others  skilled  in  operating 
any  one  machine,  still  others  engaged  in  buying  for 
the  factory,  more  in  selling,  and  still  others  in  conduct- 
ing correspondence  and  keeping  records  of  costs,  in 
paying  wages,  in  negotiating  with  banks  for  funds, 
others  in  inventing  new  improvements.  This  assign- 
ment of  special  duties  to  each  individual  is  known  as 
the  division  of  labor,  and  while  the  system  created 
opportunities  for  advancement  to  higher  grades  re- 
quiring more  skill,  better  mental  equipment,  or  con- 
centration of  effort  n  those  fitted  by  nature  or  educa- 
tion to  advance,  it  had  also  the  effect  of  clearly  marking 
off  the  unfit,  and  in  some  cases  tended  to  keep  them 
unfit.  For  when  a  man  has  learned  to  do  only  one 
thing,  and  is  worked  too  hard  at  it,  he  is  too  tired  to 


ECONOMIC  CONSEQUENCES  287 

learn  to  do  something  more  difficult  and  stays  in  his 
class.  It  appears  from  the  old  books  on  the  subject 
that  this  latter  condition  was  most  common,  and  that 
the  unskilled  were  much  abused,  and  had  a  very  hard 
time.  The  workers,  having  learned  to  do  one  thing 
for  wages,  were  dependent  for  their  living  on  the  wages 
they  could  earn,  for  from  these  wages  everything  they 
needed  had  to  be  bought,  and  they  could  not  advance 
unless  they  learned  to  do  something  more  difficult,  but 
with  ever  increasing  competition  among  themselves, 
because  there  was  less  and  less  of  the  skilled  work  to 
be  done.  The  factory  owner,  to  get  as  much  product 
from  his  machinery  per  day  as  possible,  increased  the 
working  day,  and  cases  are  on  record  noting  a  working 
day  of  sixteen  hours,  which  was  so  exhausting  as  to  kill 
ambition  and  study.  The  factory  owners  also  estab- 
lished kitchens  to  feed  their  own  people,  and  in  some 
cases  they  erected  cottages  to  keep  them  near  by,  thus 
putting  them  more  and  more  in  the  power  of  the  fac- 
tory owner,  who,  when  unscrupulous,  could  feed  them 
badly,  clothe  them  badly,  make  them  work  in  poorly 
lighted  rooms  without  sanitary  conditions,  seriously 
injuring  their  health  and  taking  from  them  all  the 
pleasures  of  life  and  prospects  for  betterment.  The 
performing  of  the  manufacturing  operations  by  machines 
divided  the  total  number  of  operations  into  a  large 
number  of  steps,  some  of  them  machine  steps  and  some 
of  them  hand  steps.  Some  of  these  things  that  had  to 
be  done  were  very  simple,  so  simple  that  a  child  could 
do  them;  and  the  desire  of  the  factory  owner  to  get 
each  operation  done  as  cheaply  as  possible  led  him  to 
employ  children  to  do  those  things  that  they  could  do, 


288  POWER 

and  women  to  do  other  things.  These  women  and 
children  had  no  more  pleasures,  no  shorter  hours,  no 
more  sanitary  surroundings  than  the  men.  For  a 
time  the  conditions  of  these  factory  workers  seem  to 
have  been  most  miserable;  then  began  a  reaction,  the 
reaction  for  adjustment  of  conditions  extending  in  one 
form  or  another  to  our  present  time,  which  adjustment 
took  place  partly  by  force  and  partly  by  intelligent 
cooperation. 

For  a  long  time  nothing  but  force  was  used,  and 
probably  it  was  the  best  way;  it  began  with  philan- 
thropic agitation  and  labor  unions  directed  toward 
reform  through  legislation,  and  the  statute  books  of 
practically  all  industrial  nations  contain  acts  controlling 
the  hours  of  labor,  restricting  the  employment  of  women 
and  children,  requiring  the  maintenance  of  sanitary, 
healthful  surroundings  in  the  workrooms,  and  in  some 
places  providing  for  accident  compensation  or  em- 
ployees' pensions.  At  the  present  time  a  new  attitude 
toward  these  questions  is  beginning  to  take  root,  in- 
volving a  reduction  of  appeal  to  force  and  the  substitu- 
tion of  cooperation;  but  from  the  time  that  the  evil 
conditions  began  to  be  noticed  almost  up  to  the  present 
we  find  a  condition  of  industrial  warfare,  workman 
against  employer,  labor  against  capital.  For  a  long 
time  this  condition  was  believed  to  be  absolutely  neces- 
sary because  it  seemed  clear  that  the  two  interests  were 
opposed,  and  on  this  ground  all  sorts  of  movements 
were  organized,  practically  all  involving  the  assertion 
of  right  based  on  might,  that  is,  up  to  recent  times. 
It  must  be  understood  that  these  conflicts  were  not 
confined  to  the  manufacturing  industries,  even  though 


ECONOMIC   CONSEQUENCES  289 

these  were  responsible  to  so  large  a  degree  for  the  sharp 
drawing  of  the  lines  of  division  between  the  two  classes. 
As  a  matter  of  fact,  much  of  the  most  bitter  of  this  sort 
of  war  was  fought  outside  of  the  ranks  of  what  might 
be  called  the  machine  industries,  and  it  is  a  most  sig- 
nificant fact  that  these  particular  industries  are  to-day 
pointing  the  way  toward  a  betterment  of  conditions 
that  shall  be  permanent,  and  that  shall  involve  right 
and  not  might.  In  these  machine  industries,  where  the 
study  of  nature's  processes,  forces,  energy,  and  sub- 
stances has  resulted  in  so  much  undoubted  good  for 
all,  similar  study  of  man-controlling  forces  is  meeting 
with  equal  success.  It  is  sometimes  stated  that  the 
evil  conditions  that  came  with  the  creation  of  the  fac- 
tory system,  in  times  when  society  was  not  organized 
to  apply  a  remedy  and  avoid  abuses  of  the  new  found 
forces,  are  responsible  for  the  creation  of  the  trade- 
unions,  but  this  is  not  the  case  any  more  than  the 
assumption  that  labor  abuses  did  not  exist  before  the 
factory  system.  The  trade-union,  as  a  matter  of  fact, 
while  it  played  an  important  part  in  the  change  of  these 
conditions,  was  not  a  creation  or  product  of  the  factory 
system,  as  the  following  quotation  from  the  "  History 
of  Trade  Unionism,"  by  Sidney  and  Beatrice  Webb, 
will  show:  "It  is  often  assumed  that  the  divorce  of 
the  manual  worker  from  the  ownership  of  the  means  of 
production  resulted  from  the  introduction  of  machinery, 
and  the  factory  system  was  responsible  for  the  trade- 
unions.  Had  this  been  the  case  we  should  not,  upon 
our  hypothesis,  have  expected  to  find  trade-unions  at 
an  earlier  date  than  factories,  or  in  industries  un- 
transformed  by  machinery.  The  fact  that  the  earliest 


290  POWER 

combinations  of  wage-earners  in  England  precede  the 
factory  system  by  half  a  century  and  occur  in  trades 
carried  on  exclusively  by  hand  labor,  reminds  us  that 
the  creation  of  a  class  of  lifelong  wage-earners  came 
about  in  more  than  one  way."  For  example,  the 
master  tailors.  "  The  master  tailors  in  1720  complained 
to  Parliament  that  the  journeyman  tailors  about  the 
cities  of  London  and  Westminster,  to  the  number  of 
7000  and  upward,  have  lately  entered  into  a  combina- 
tion to  raise  their  wages  and  leave  off  working  an  hour 
sooner  than  they  used  to  do."  "It  is  easy  to  under- 
stand how  the  massing  together  in  factories  of  regi- 
ments of  men  all  engaged  in  the  same  trade,  facilitated 
and  promoted  the  formation  of  journeymen's  trade 
societies,  but  with  the  cotton  spinners,  as  with  the 
tailors,  the  rise  of  permanent  trade  combination  is  to 
be  ascribed  in  a  final  analysis  to  the  definite  separation 
between  the  functions  of  the  capitalist  and  the  manual 
worker,  that  is  to  say,  the  direction  of  industrial  opera- 
tions and  their  execution.  Only  in  those  industries 
in  which  the  worker  has  ceased  to  be  concerned  in  the 
profit  of  buying  and  selling  can  effective  and  stable 
trade  organizations  be  established."  "It  appears  to 
us  from  these  facts  that  trade-unionism  would  have 
been  a  feature  of  English  industry  even  without  the 
factory  system." 

Just  what  part  trade-unionism  played  in  the  attack 
on  these  factory  abuses  is  not  quite  clear,  but  that  there 
were  vigorous  attacks  and  that  there  were  real  abuses, 
there  can  be  no  doubt.  As  an  illustration  concerning 
the  older  feelings  on  this  subject,  note  the  following 
quotation  from  a  little  book,  written  in  1836  by  P. 


ECONOMIC   CONSEQUENCES  291 

Gaskell,  entitled  "  Artisan  and  Machinery  "  :  "It  would 
have  been  well  if  steam  and  mechanism,  in  breaking 
up  a  healthy,  contented  and  moral  body  of  laborers, 
had  provided  another  body,  possessing  the  same  ex- 
cellent qualities  as  men  and  citizens,  but  it  has  not  been 
so."  This  is  offered,  not  as  representing  anything  that 
is  now  true,  but  as  an  indication  of  the  feeling  at  the 
time  of  writing,  1836,  concerning  these  abuses.  Even 
John  Ruskin,  whose  literary  productions  have  met 
with  admiration  among  those  capable  of  judging, 
blamed  the  mechanical  inventions  and  industrial 
progress  for  about  everything  that  he  noticed  wrong 
in  the  organization  of  society. 

Abuses  of  the  laboring  classes  as  well  as  the  divorce 
of  the  functions  of  capitalist  and  manual  worker  existed 
in  other  industries  before  the  factory  era,  and  it  is  well 
known  that  even  at  the  time  when  this  began  coal  was 
being  carried  from  English  mines  on  the  backs  of  women. 
As  a  matter  of  fact,  it  is  in  the  factory  management 
of  labor  and  machinery  to-day  that  this  most  perplex- 
ing source  of  social  unrest  is  being  gradually  solved; 
and  the  solution  will  be  based  on  the  general  acceptance 
of  that  most  fundamental  proposition,  that  the  interests 
of  worker  and  capitalist  employer  are  not  only  not 
diametrically  opposed,  but  absolutely  identical,  all  of 
which  appears  more  clearly  when  it  is  realized  that  the 
wealth  of  the  world  is  not  a  fixed  quantity,  and  that 
he  who  gains  does  not  necessarily  take  from  another 
who  loses.  We  may  assume  that  wealth  is  anything 
that  somebody  wants,  or  its  equivalent  in  the  means  to 
secure  it.  Now  the  very  act  of  manufacturing  makes 
something  new  out  of  something  old,  makes  something 


292  POWER 

useful  out  of  a  useless  thing,  or  makes  from  something 
that  nobody  wants  something  that  somebody  does 
want,  or  from  something  of  value  something  of  greater 
value  in  point  of  desire  to  possess  it.  Often  the  new 
article  is  something  never  heard  of  before,  but  which 
is  wanted  as  soon  as  seen,  witness  the  automobile, 
the  electric  light,  the  gas  cook-stove,  or  the  rubber 
boot.  From  this  point  of  view,  not  only  is  the  product 
of  the  farm,  sea,  forest,  or  mine  wealth,  but  the  opera- 
tion of  every  manufacturing  machine  in  the  land 
is  most  positively  a  wealth-producing  process.  The 
last  census  report  showed  an  increase  in  money  value 
of  nearly  80  per  cent  by  the  manufacturing  operations 
on  the  raw  material.  So  also  is  transportation.  The 
rubber  that  grows  on  the  banks  of  the  Amazon  is  just 
about  useless  to  the  natives.  It  is,  however,  a  very 
much-desired  and  high-priced  article  here.  Traveling 
through  the  country  will  show  every  fall  thousands 
of  barrels  of  apples  lying  on  the  ground  rotting,  while 
apples  in  town  bring  a  good  price,  which  indicates  how 
much  they  are  wanted.  That  which  is  wanted  in  one 
place  may  perhaps  be  quite  useless  in  another.  The 
application  of  machinery  to  transportation  and  manu- 
facture has,  then,  been  a  great  wealth  producer,  and 
trade  and  commerce  may  likewise  be  so  regarded  from 
this  point  of  view.  However,  the  more  primary,  the 
more  direct  of  the  two,  as  wealth  producers,  are  the 
manufacturing  processes  rather  than  transportation 
or  commerce.  Having  produced  something  useful,  or 
in  more  desirable  form,  from  something  less  desirable, 
the  manufacturer  finds  it  possible  to  secure  a  profit 
for  his  skill,  skill  in  carrying  out  the  operations  re- 


ECONOMIC  CONSEQUENCES  293 

quired  for  the  transformation  of  substances,  skill  in 
gathering  money  necessary  to  carry  on  the  work,  skill 
in  managing  men,  in  buying  and  selling.  On  the  other 
hand,  the  worker  has  only  his  time  and  special  skill  of 
hand  or  brain  to  offer  for  service  with  the  capital  and 
other  sort  of  skill  of  the  employer ;  together  they  pro- 
duce wealth  which  may  be  shared  to  the  profit  of  both, 
in  proportion  to  the  contribution  of  each,  without  taking 
anything  from  anybody  else.  Of  course,  if  either 
party  tries  to  take  the  whole  gain,  the  other  may  not 
be  criticized  for  fighting  for  his  share,  no  matter  which 
one  it  is.  Now,  the  share  of  the  worker  is  represented 
by  his  wages,  and  the  share  of  the  employer  by  his 
profits ;  if  either  takes  more  than  he  should,  the  public 
that  buys  the  product  pays  the  bill.  It  is  to  the  inter- 
est of  the  public  as  a  whole,  therefore,  to  know  some- 
thing of  this  sharing  problem,  one  phase  of  which  is 
the  effort  of  the  worker  to  secure  more  and  more 
wages  regardless  of  work  done,  and  the  other  that  of 
the  manufacturer  to  get  as  much  for  his  product  as 
he  can  after  paying  the  wage  demand  and  for  material 
and  the  capital  and  skill  used  in  management.  Com- 
petition is  often  considered  a  sufficient  force  to  regulate 
the  prices  of  manufactured  goods,  while  the  fixing  of 
wages  and  salaries,  being  subject  to  no  such  automatic 
principle,  has  been,  and  is  yet,  a  bone  of  contention. 
Intelligent  study  of  this  problem  by  engineers  of  great 
breadth  is,  however,  producing  effects,  and  it  is  inter- 
esting to  note  that  greater  progress  is  being  made  in 
the  industries  in  which  machinery  plays  an  important 
part,  and  in  this  country  more  than  in  any  other. 
In  the  industrial  history  yet  to  be  written,  engineers 


294  POWER 

like  Taylor,  Gannt,  and  Emerson,  whose  philosophic 
studies  of  the  problem  are  producing  practical  results 
that  are  now  recognized,  will  rank  with  Watt  and 
Arkwright  as  benefactors,  pioneers  in  the  movement 
to  minimize  waste  of  labor  by  proper  systems  of  com- 
pensation and  management,  as  has  already  been  done 
by  the  substitution  of  machine-work  for  so  much  of 
hand  labor.  Nothing  but  good  can  result  from  the 
most  efficient  use  of  nature's  materials,  nature's  energy, 
and  the  power  derived  from  it,  and  last,  but  not  least, 
the  most  efficient  use  of  man's  own  effort  and  ability. 
More  can  be  done  and  is  now  being  done  for  the  general 
good  in  the  minimizing  of  labor  waste  by  trained  engi- 
neers to-day,  with  a  corresponding  increase  of  indus- 
trial peace  and  social  welfare,  than  has  been  done  in 
almost  a  century  of  legislation,  or  by  the  teachings  of 
economists  and  sociologists  of  the  old  school. 

Few  beside  those  who  have  studied  the  question  have 
any  idea  of  the  enormity  of  labor  waste  to-day,  and, 
therefore,  of  how  much  less  things  might  cost  than  they 
do,  and  of  how  much  higher  wages  might  be  paid  with- 
out reducing  profits,  and  in  spite  of  reduction  of  prices. 
All  modern  scientific  profit-sharing  and  fair  wage- 
systems  are,  however,  based  on  the  study  of  these  things. 
Mr.  Harrington  Emerson  tells  of  a  shop  in  Cincinnati 
where  a  certain  part  of  a  machine  had  been  made  regu- 
larly by  good  men  in  thirty-four  hours,  and  it  was 
claimed  by  the  workmen  that  this  was  a  fair  and  proper 
time.  By  offering  inducements  that  time  was  changed, 
and  the  same  work  is  now  done  regularly  in  ten  hours. 
A  similar  case  was  reported  by  Mr.  Fred  W.  Taylor, 
at  the  Bethlehem  Steel  Co.,  some  years  ago,  where 


ECONOMIC   CONSEQUENCES  295 

laborers  loading  pig-iron  on  cars  averaged  about  12 
tons  per  day,  but  after  inducements  were  offered  this 
was  increased  to  45  tons  per  day.  Another  case,  re- 
ported by  him  at  the  Mid  vale  Steel  Co.,  showed  that 
the  turning  or  finishing  of  certain  large  forgings  was 
done  at  the  rate  of  four  or  five  pieces  per  day,  which 
was  increased  to  ten  pieces  per  day  without  serious 
tax  after  the  men  were  induced  to  try.  One  of  the 
most  earnest  and  practical  engineers  studying  this 
problem  and  applying  remedies  is  Mr.  H.  L.  Gannt, 
and  we  cannot  do  better  than  quote  his  summary  of 
the  situation  from  some  lectures  delivered  on  the  sub- 
ject before  the  students  of  Mechanical  Engineering 
at  Columbia  University. 

"  In  any  discussion  on  the  relations  between  employer 
and  employed  we  must  recognize  the  fact  that  in  the 
majority  of  cases  men  still  act  on  the  principle  that 
1  they  should  take  who  have  the  power,  and  they  should 
keep  who  can.'  As  long  as  the  interests  of  the  em- 
ployer and  employed  seem  antagonistic,  there  will  be 
conflict,  and  in  any  discussion  of  the  subject  we  must 
recognize  that  antagonism  means  conflict.  Until  we 
can  find  some  means  of  doing  away  with  the  antagonism, 
the  conflict  will  continue. 

"  If  the  amount  of  wealth  in  the  world  were  fixed,  the 
struggle  for  the  possession  of  that  wealth  would  neces- 
sarily cause  antagonism;  but,  inasmuch  as  the  amount 
of  wealth  is  riot  fixed,  but  constantly  increasing,  the 
fact  that  one  man  has  become  wealthy  does  not  neces- 
sarily mean  that  some  one  else  has  become  poorer,  but 
may  mean  quite  the  reverse,  especially  if  the  first  is  a 
producer  of  wealth.  The  production  of  wealth  can  be 


296  POWER 

so  greatly  facilitated  by  the  cooperation  of  employer 
and  employed  that  it  would  seem  that  if  the  new  wealth 
were  distributed  in  a  manner  that  had  in  it  even  the 
elements  of  equity,  neither  party  could  afford  to  have 
the  working  arrangement  disturbed. 

"As  long,  however,  as  one  party,  no  matter  which, 
tries  to  get  all  it  can  of  the  new  wealth,  regardless  of 
the  rights  of  the  other,  conflicts  will  continue. 

"  It  is  undeniable  that  unions  have  advanced  the  cause 
of  workmen  in  general,  and  we  must  not  blame  them 
for  using  force  to  accomplish  their  ends.  It  was  the 
only  means  they  had.  If  we  wish  them  to  use  any  other 
means,  we  must  provide  them  with  a  means  that  they 
will  consider  more  desirable,  and  that  will  give  better 
results,  for  in  this  country  so  long  as  a  man  conforms 
to  the  laws  of  the  state,  he  has  a  right  to  govern  his 
actions  in  such  a  manner  as  his  interests  seem  to  dic- 
tate. Men  join  the  union  because  they  think  they 
will  be  better  off  in  the  long  run  for  being  in  the  union. 
The  idea  of  the  union  is  to  get  a  higher  rate  of  wages 
for  the  whole  class,  because  in  general  nobody  in  that 
class  can  get  a  substantially  higher  rate  unless  the 
whole  class  gets  a  higher  rate. 

"  The  employer  generally  pays  but  one  rate  of  wages 
to  one  class  of  workmen,  because,  as  a  rule,  he  has  no 
means  of  gauging  the  amount  of  work  each  man  does. 

"  Under  ordinary  conditions,  where  there  is  no  union, 
the  class  wage  is  practically  gauged  by  the  wages  the 
poor  workman  will  accept,  and  the  good  workman  soon 
becomes  discouraged  and  sets  his  pace  by  that  of  his 
less  efficient  neighbor. 

"  Increase  of  efficiency  is  essentially  a  problem  of  the 


ECONOMIC   CONSEQUENCES  297 

manager,  and  the  amount  to  which  efficiency  can  be 
increased  by  proper  management  is  so  great  in  most 
cases  as  to  be  almost  incredible. 

"  There  are  only  two  methods  of  paying  for  work. 
One  is  for  the  time  the  man  spends  on  the  work,  and  the 
other  is  for  the  amount  of  work  he  does.  The  first  is 
day-work.  The  second  is  piece-work.  All  other  sys- 
tems, whatever  may  be  their  names,  are  combinations 
of  these  two  elementary  methods  in  different  propor- 
tions. It  is  natural  that  the  employer  should  wish 
to  get  all  the  work  he  can  for  the  money  he  spends. 
It  is  also  natural  that  the  workman  should  wish  to  get 
all  the  money  he  can  for  the  time  he  spends.  Any 
other  condition  would  be  wrong,  would  be  almost 
suicidal.  These  two  conditions  seem  to  be  so  antag- 
onistic that  most  people  give  up  any  attempt  to  har- 
monize them  and  adopt  a  scheme  of  bargaining.  Under 
such  a  system  the  most  aggressive  group  or  the  one  that 
has  the  most  favorable  conditions  wins  in  the  long 
run. 

"  Day-work  is  of  two  classes:  first,  ordinary  day-work, 
in  which  there  is  no  attempt  to  get  individual  records 
and  every  man  of  a  class  receives  the  same  wages,  re- 
gardless of  the  amount  of  work  he  does ;  the  second, 
that  in  which  the  work  is  carefully  planned  beforehand 
so  each  man  can  have  continuous  work,  and  so  that 
an  exact  record  can  be  kept  of  what  he  does  and  his 
rate  of  pay  adjusted  accordingly. 

"  The  first  method  leads  the  good  men  to  organize  a 
union.  In  the  second  class  of  day-work  some  intelli- 
gent man  studies  the  work  to  be  done,  lays  it  out  care- 
fully, provides  the  proper  appliances,  divides  it  up  in 


298  POWER 

such  a  manner  that  it  can  be  done  by  individuals  or 
by  small  gangs,  so  that  an  exact  record  can  be  kept  of 
what  each  individual  or  gang  does  and  compensation 
paid  accordingly.  Such  a  method  of  handling  work- 
men has  exactly  the  reverse  effect,  and  their  efficiency 
begins  to  increase  at  once.  When  we  increase  one 
man's  wages  because  his  record  shows  he  deserves  it, 
it  not  only  does  not  cause  trouble  with  the  other  work- 
men, but  it  acts  as  a  stimulus  to  them.  To  carry  out 
this  plan  there  must,  however,  be  created  a  system  of 
training  men  and  teaching  them  the  most  efficient  way 
to  get  the  work  done. 

"  If,  then,  you  train  a  man  to  be  efficient  and  adopt  a 
system  of  management  which  enables  him  to  utilize 
all  of  his  energies  in  productive  work,  you  can  afford 
to  pay  him  far  higher  wages  than  he  can  get  where  the 
workmen  are  not  trained,  and  where  the  system  of 
management  is  not  such  as  will  enable  him  to  work 
continuously  and  efficiently. 

"  If  you  keep  an  exact  record  of  what  each  worker 
does,  surround  the  men  with  conditions  under  which 
they  can  work,  and  compensate  the  efficient  one  liberally, 
no  man  will  spend  his  spare  time  trying  to  find  out  how 
to  raise  the  wages  of  the  other  fellow.  Workmen,  as  a 
rule,  will  do  more  work  if  their  earnings  are  increased 
by  so  doing,  and  you  will  find  great  difficulty  in  getting 
the  efficient  ones  into  labor  unions  if  they  are  not 
benefited  by  joining  them. 

"  The  second  system  of  paying  wages  is  called  piece- 
work. In  the  term  'piece- work'  we  include  all  the 
schemes  for  compensating  men  for  what  they  do  in- 
stead of  for  the  amount  of  time  they  work.  It  may  be 


ECONOMIC  CONSEQUENCES  299 

divided  into  two  classes,  the  first  in  which  the  price 
of  a  job  is  set  from  previous  records  or  from  the  estimate 
of  a  foreman,  who  generally  considers  his  work  done 
when  he  has  set  the  price.  The  second  system  of  piece- 
work, when  properly  operated,  provides  a  complete 
system  of  instruction  for  the  workman,  equitable 
compensation  for  his  efforts,  and  opportunity  for 
advancement  on  his  own  merits  and  not  through  pull 
or  friendship.  The  essentials  of  this  system,  which 
have  never  failed  to  create  a  system  of  harmony  and 
cooperation,  are :  - 

"  a.  To  have  the  very  best  expert  available  investi- 
gate in  detail  every  piece  of  work,  and  find  out  the  best 
method  and  the  shortest  time  for  doing  it  with  the 
appliances  to  be  had. 

"  b.  To  develop  a  standard  method  for  doing  the  work 
and  to  set  the  maximum  time  which  a  good  workman 
should  need  to  accomplish  it. 

"  c.  To  find  capable  workmen  to  do  the  work  in  the 
time  and  manner  set,  or  to  teach  an  ordinary  workman 
to  do  it. 

"  d.  When  high  efficiency  has  been  attained,  to  com- 
pensate, not  only  the  workman  actually  doing  the  work, 
but  also  those  who  supply  him  with  materials  and  appli- 
ances to  enable  him  to  maintain  the  efficiency  specified. 

"  e.  To  find  among  the  workmen  who  have  learned 
the  best  ways  of  doing  the  work  some  that  can  investi- 
gate and  teach,  and  thus  gradually  get  recruits  for  the 
corps  of  experts  so  that  the  system  may  be  self-per- 
petuating. 

"/.  The  ordinary  foreman  of  the  shop  must  not  be 
called  upon  to  do  the  work  of  the  expert. 


300  POWER 

u  It  is  a  well-recognized  fact  that  the  efficient  man 
at  high  wages  is  much  more  profitable  to  his  employer 
than  the  inefficient  man  at  lower  wages. 

"  Inasmuch  as  the  efficient  workman  often  does  two  or 
three  times  as  much  as  the  poor  workman,  and  does  it 
better,  and  inasmuch  as  the  workman  who  does  twice  as 
much  work  cuts  the  general  expense  per  unit  of  output 
in  half,  there  would  seem  to  be  no  question  that  such 
a  system  of  training  would  pay  handsomely." 

All  this  is  sound  practical  philosophy,  and  its  ex- 
tensive application  will  do  a  great  deal  toward  not 
only  the  reduction  of  capital  and  labor  conflicts,  and 
the  limination  of  erroneous  and  unsound  ideas  as  to 
necessary  opposition  of  interests,  but  it  will  do  far 
more  —  it  will  have  a  world-wide  effect,  for  increase 
of  efficiency  of  labor  must  necessarily  have  the  same 
result  as  the  use  of  labor-saving  machinery  has  had, 
since  it  enables  one  man  to  do  the  work  of  two,  three, 
or  four.  It  is  sometimes  assumed  that  this  sort  of 
thing  will  mean  the  throwing  out  of  employment  of 
those  no  longer  necessary,  and  it  would  if  it  all  happened 
in  a  minute,  but  it  will  not  if  it  happens  in  the  naturally 
slow  way.  Early  spinning  and  weaving  machinery 
was  smashed  by  the  hand  workmen,  who  thought  there 
would  be  no  more  demand  for  them;  yet  the  use  of  it 
so  decreased  the  cost  of  cloth  that  the  sales  increased 
doubly  fast,  in  a  short  time  more  weavers  and  spinners 
were  at  work  than  ever  before,  and,  moreover,  their 
labor  was  by  no  means  so  fatiguing  or  wearing  as  ma- 
chine attendants  as  it  was  as  hand  workers.  Precisely 
the  same  thing  has  happened  in  all  lines ;  increased 
efficiency  of  workers,  either  by  working  faster  or  by 


ECONOMIC  CONSEQUENCES  301 

machine  assistance,  however  much  it  might  seem  to 
harm  the  class  at  first,  has  always  benefited  the  class 
itself  and  the  whole  community  by  decreased  prices, 
increased  consumption,  and  all-round  better  living. 

There  is  absolutely  no  doubt  that  the  use  of  machin- 
ery and  power  is  on  the  increase,  that  every  old  machine 
is  constantly  being  studied  to  devise  ways  of  improving 
it,  and  that  equally  deep  study  of  the  efficiency  of  labor, 
its  proper  compensation  and  welfare,  will  receive 
ever-increasing  attention  of  the  analytical  sort,  and 
that  all  the  effects  of  this  will  be  in  the  main  beneficial 
and  elevating  to  that  nation  that  makes  the  greatest 
progress.  What  effect,  then,  will  such  an  increase  have 
on  the  conditions  of  living  of  the  future  ?  Will  the 
flow  to  the  cities  continue,  will  more  manufacturing 
cause  more  cities,  and  if  so,  how  is  this  tremendous 
congestion  of  population  to  be  housed  and  fed  ?  While 
it  is  true  that  in  the  early  days  the  factory  created  the 
city,  to-day  it  is  not ;  it  is  breaking  up  the  city,  and  the 
reason  is  sound.  Highest  efficiency  of  processes  and 
lowest  cost  of  product  demand  saving  in  every  way 
possible,  so  that  the  factory  that  can  do  its  work  in 
the  country  or  small  town  simply  cannot  afford  to  stay 
in  the  city.  It  does  not  take  a  highly  refined  study  to 
show  how  absurd  it  would  be  to  build  steel  works  at 
Broadway  and  Wall  Street,  when  there  are  thousands 
of  square  miles  of  cheap  land  within  reach  of  railroads. 
This  fact  alone  will  be  sufficient  to  explain  the  ten- 
dency, now  so  common  and  ever  on  the  increase,  of 
relocating  factories  in  small  towns,  or  creating  new 
towns  in  the  open  country  as  is  being  done  at  Gary, 
Indiana,  by  the  United  States  Steel  Co.,  and  indicates 


302  POWER 

that  the  city,  if  it  is  to  increase  at  all,  must  find  that 
increase  based  on  other  causes.  Statistics  show  that 
while  there  is  still  a  flow  toward  cities  it  has  changed 
in  character.  Weber,  in  his  "  Growth  of  Cities/'  says: 
"The  most  rapid  rate  of  increase  of  population  is  found 
in  villages  and  small  towns  (2500  to  800)  which  are 
chiefly  dependent  for  their  prosperity  upon  manufac- 
turing industries.  The  great  cities,  centers  of  trade 
and  commerce,  nearly  rival  the  villages  in  rate  of 
growth."  Here,  then,  is  the  key,  —  the  large  cities 
are  becoming,  not  the  centers  of  manufacturing,  but 
centers  of  trade  and  commerce,  and  their  location  and 
growth  are  now  traceable  to  two  causes,  commercial 
and  social.  They  will  locate  wherever  there  is  a  break 
in  the  transportation;  railroad  terminals,  shipping 
ports,  or  points  of  transfer  are  to  be  city  sites  as  they 
always  have  been.  Their  growth  seems  to  be  dependent 
just  as  strongly,  however,  on  social  conditions,  described 
by  Mr.  E.  S.  Smith  as  follows :  - 

"Man  naturally  loves  company  and  good  fellowship. 
This  seems  to  be  the  real  basis  of  the  drift  from  farms 
to  the  cities.  All  the  attractions  of  city  life  are  spread 
in  the  literature  of  the  day.  Men  come  to  know  more 
about  the  life  outside  of  their  own  little  horizon,  and 
become  restless  to  share  other  and  more  attractive 
callings.  In  the  country  it  is  quiet,  with  few  pleasures, 
but  in  the  city  there  is  the  hurry  and  excitement,  stir 
and  push  of  business,  amusements  of  every  sort,  re- 
sorts of  every  grade  where  men  may  congregate  and 
pass  the  time  in  congenial  companionship.  In  the 
city  also  are  the  great  educational  institutions,  museums, 
art  collections,  each  making  its  appeal  to  the  different 


ECONOMIC  CONSEQUENCES  303 

types  of  man.  There  is  a  higher  standard  of  living. 
Every  man  enjoys  the  comforts  and  luxuries  of  life." 
While,  therefore,  as  a  result  of  good  transportation 
and  cheaper  land  in  the  small  towns  the  manufactures 
will  no  longer  be  causal  influences  in  city  growth  directly, 
they  do,  nevertheless,  draw  more  and  more  on  the  farm 
or  food-producing  element  of  the  population,  which 
must  be  recruited,  when  the  danger  point  is  reached, 
not  from  the  manufacturing  and  transportation  work- 
ing classes,  but  from  the  small  trader  class,  with  which 
the  large  cities  swarm,  and  who  seem  to  prefer  an 
approach  to  starvation  in  the  excitement  of  the  city 
with  but  light  labor  to  good,  honest,  hard  work  on  farm 
or  in  factory.  This  danger  point  will  not  be  reached, 
however,  for  some  time  to  come,  for  although  the  farm 
population  has  been  ever  on  the  decrease  in  proportion 
to  the  city  dweller,  the  output  of  the  farm  has  been 
keeping  pace  fairly  well  by  the  application  of  the  same 
principles  of  efficiency  so  highly  developed  in  manu- 
facture. In  the  United  States,  Weber  says  that  the 
farm  population  was  about  97  per  cent  of  the  whole, 
which  had  decreased  in  1890  to  about  70  per  cent,  and 
is  probably  less  to-day.  Yet  increase  of  farming  effi- 
ciency seemed  to  more  than  keep  pace ;  for  example, 
Powell  shows  that  from  1896  to  1908  the  whole  popu- 
lation increased  24  per  cent,  whereas  the  agricultural 
exports  increased  in  the  same  time  53  per  cent,  or  more 
than  twice  as  much.  With  regard  to  this  same  ques- 
tion of  efficient  farming,  Davidson  and  Chase,  in  their 
book  on  "Farm  Machinery,"  make  the  interesting 
comment  that  there  were  never  over  400,000  Indians 
in  North  America,  yet  they  were  often  in  want  of  food. 


304  POWER 

Up  to  the  year  1850  the  old-fashioned  hand  methods 
of  farming  sufficed  to  maintain  the  balance  fairly 
well,  but  at  that  time  the  steam-engine  began  to  appear 
and  stimulated  the  use  of  farming  machinery.  To-day 
practically  everything  can  be  done  by  machine  when 
the  farm  is  large  enough  to  warrant  its  purchase.  Plow- 
ing may  be  done  by  traction  engines  run  by  gasolene 
or  kerosene  ;  the  seed  planted  by  horse-drawn  machines; 
grain  cut  and  threshed,  or  corn  picked  and  shelled  ready 
for  market ;  cream  separated  from  milk,  churned,  and 
butter  made ;  water  pumped  for  stock  and  irrigation 
by  power-driven  machines ;  all  of  which  remove  the 
drudgery,  and,  taken  together  with  the  rotation  of 
crops,  cultivation,  and  the  use  of  proper  fertilizers  and 
insect-destroying  methods,  enormously  increase  the 
productiveness  of  both  the  acre  of  ground  and  the  man 
who  tends  it.  In  America,  we  have  never  had  an 
abundance  of  farm  labor,  but  the  American  inventor 
has  surpassed  the  world  in  his  ability  to  devise  machines 
and  methods,  without  which  this  country  could  never 
have  been  supplied  with  food;  and  this  same  ability, 
that  has  rendered  efficient  the  manufacturing  system, 
may  be  relied  upon  to  continue  to  build  up  both,  with 
continued  and  permanent  prosperity  for  the  nation 
that  teaches  its  sons  how  to  patiently  study  the  little 
things  which  control  the  large  ones,  however  remote 
the  connection  may  seem  to  him  who  has  not  studied 
both  profoundly  and  widely. 


INDEX 


Accessories  of  the  boiler  plant,  67,  85 
Aeroplane,    Gasolene    engine    funda- 
mental to  the,  204 
Air  and  water  in  motion,  7,  16,  29 
Air,   needed  in   combustion,   67,   69, 
84-85  ;    proper  control  of,  supplied 
to  furnaces,  105  ;  in  explosive  mix- 
tures,  163 ;    in  gas-producer,   185- 
87  ;   in  carbureter,  202,  203 
Air,    Compressed,    transmission   sys- 
tems, 268-69 

Air-cooled  type  of  motor,  154-55 
Air-pump  or  vacuum-pump,  126 
Air-valve  for  carbureter,  202 
Alcohol,  Materials  for  conversion  into, 

26;    denatured,  201,  205 
Allis-Chalmers  Co.,  Milwaukee,  Ma- 
chine shop  of  the,   21  ;    pumping- 
engine,  53  ;    turbine  built  by  the, 
236-37 
American   inventor,    Ability   of   the, 

304 

Angle-compound  engine,  114,  116 
Animas    Co.,    Cascade    Creek,    Col., 

Dam  of  the,  248 

Anthracite  coal,  Exhaustion  of  known 
supply  of,  24  ;  gasifying  of,  183-86  ; 
the  process,  184-85 
Arkwright,  Improvement  in  spinning 

by,  61 

Asphalt  from  natural  oil,  200 
Atmospheric  gas-engine,  55 
Atmospheric  pressure,  Use  of,  45-47, 
55  ;    pounds  of,  46  ;    height  water 
is  raised  by,  46 ;    in  gas-engine  of 
Huygens,  55 

Atmospheric  steam-engine,  45—47,  54 
Automobile,  Gasolene  engine  funda- 
mental to  the,  204 
Automobiles,    Number  of,   built   an- 
nually, 204 


Baffles  for  hot  gases,  76-77,  78,  79 
Baker,   Walter,   Co.,  Vertical  engine 

in  factory  of,  50,  51 
Banking,  Industrial,  285-86 
Barometer,  Action  of  the  ordinary,  46 
Barometric  type  of  condenser,  132-35 
Beehive  oven  for  making  coke,   gas 

wasted,  180-82 

Belts,  Transmission  of  power  by,  267 
Bituminous  coal,  Duration  of  supply 
of,  25  ;    melting  and  caking  of,  in 
roasting,   181  ;    caused  by  the  tar 
in  the  coal,  183  ;   gasifying  of,  192- 
98 ;    real  difficulties  with,  199 
Blast-furnace    gas    utilized    in    gas- 
engines,   179-80 
Blow-guns,  43 

Blowing-engine,  The,  47 ;  of  the  Re- 
public Iron  and  Steel  Co.,  53,  54 
Boilers,  Steam,  52,  67-85  ;  variety  of, 
67,  68;  general  relations  of,  69; 
shapes  of,  70-72  ;  flues  in,  71-73  ; 
Scotch  and  fire-tube,  73-75  ;  loco- 
motive, 74  ;  water-tube,  75-80  ; 
concentrated  form  of,  82-83  ;  cost 
and  efficiency  in,  83  ;  use  of  high- 
pressure,  95 

Bosnia,  Concrete  canal  at,  258 
Branca,    Impulse    steam-turbine    of. 

41-42 

Breast  wheels  in  early  low-head  de- 
velopment, 229 

Cam  to  operate  valves,  154,  171 
Canadian-Niagara  Power  House,  262- 

63 

Canals,  High-  and  low-level,  for  low- 
head  development,  229-30;  on 
the  Merrimac  and  Connecticut 
rivers,  230 ;  arrangement  of,  at 
Holyoke,  230;  257-58 


305 


306 


INDEX 


Capital  and  business,  285-86 ;  and 
labor,  286-89,  294-301 

Captains  of  industry,  4 

Carbon  dioxide  gas,  Process  of  con- 
verting, into  carbon  monoxide, 
184-86 

Carbureter,  The,  for  volatile  fuels, 
201-05  ;  varieties  of,  203,  206  ;  for 
gasolene,  201-3 ;  210 

Carnegie  Steel  Co.,  Pittsburg,  Home- 
stead Works  of  the,  21 

Cartridge  method  of  vaporizing 
heavy  oils,  209 

Cartwright,  Dr.,  The  power  loom  of, 
61 

Census  reports,  Statistics  from,  9-11 

Central  power-stations,  Average  out- 
put of,  139-41 

Centrifugal  pump,  127,  130,  134 

Chains  on  toothed  wheels,  Trans- 
mission of  power  by,  267 

Chambers,  see  High-pressure  cham- 
bers. 

Chattahoochee,  Dam  and  spillway 
on  the,  near  Columbus,  Ga.,  248- 
49 

Chattanooga,  Low-head  develop- 
ment below,  227-29 

Chicago,  Speed  of  a  journey  to,  18-19 

Circulation  in  boilers,  71,  75-76,  79, 
81-83 

Cities  becoming  centers  of  trade  and 
commerce,  302 

Clark,  F.  G.,  on  power  cost  distribu- 
tion and  station  output,  140-41 

Clearance  volume,  110 

Clermont,  The,  of  Robert  Fulton,  63, 
64 

Clinkering,  Prevention  of,  by  steam 
jets,  186-87,  190 

Coal,  the  main  fuel  dependence,  24  ; 
consumption  of,  24 ;  duration  of 
supply  of,  24-25  ;  economy  of,  68  ; 
combustion  of,  84-85 ;  efficiency 
consumption  of,  per  hour  per  h.  p., 
102  ;  losses  in  converting  one  pound 
of,  into  electricity,  137-39 ;  adap- 
tation of,  for  gas-engines,  180 ; 
roasting  processes,  180-83 ;  bee- 
hive oven  for  coke,  gas  wasted, 
180-82 ;  gas  from  bituminous, 
coke  the  waste,  182-83 


Coal-gas,  Components  of,  183 

Coal  storage  bins  under  roof,  52 

Coal  tar,  Products  from,  14 ;    183 

Coke,  Beehive  oven  for  making,  180- 
82  ;  waste  product  in  making  coal- 
gas,  182-83;  gasifying,  183-86; 
the  process,  184-86 

Combustion  chamber,  Heavy  oils 
injected  into  hot,  206-8 

Combustion  of  coal,  Conditions  of, 
84-85 

Combustion  supplies  rapid  heating 
in  gas-system,  144 ;  explosive, 
144-46  ;  spherical,  145-46 ;  waves 
in,  161-62 

Commonwealth  Electric  Co.,  Power- 
house of,  121-22 

Commerce,  Evolution  of,  283-85 

Compound  engines,  111— 15  ;  turbines 
as  auxiliaries  to,  124 

Compression  of  explosives  in  cylinder, 
151 

Condensers,  52,  95,  96 ;  forms  of, 
125-34 ;  economize  use  of  steam, 
125;  surface,  128-30;  cooling 
towers,  131-32;  spray-nozzle  sys- 
tem, 132—33  ;  barometric  type  of, 
132-35 

Condensing  water,  Loss  of  heat  to, 
137,  138 

Conditions,  Controlling,  must  be 
studied,  69 

Cooling  towers,  131-32 

Corliss  compound  engines,  114-16 

Corliss  valve,  The,  91-93 ;  gives  full 
control,  98 

Cost  and  relative  suitability,  273-75 

Cost  of  power,  139-41 

Cotton  mill,  Largest,  in  the  world,  22 

Cotton  seed,  Value  of,  14 

Cranks  to  give  rotary  motion,  47 

Crompton,  Improvement  in  spinning 
by,  61 

Cross-compound  engine,   112-14 

Curved-tube  boilers,  79-80;  for 
torpedo  boats,  81 ;  most  concen- 
trated form  of,  82-83 

Cylinder  and  piston,  Single-  and 
double-acting,  43-45 ;  spaces  at 
end  of,  110;  use  of  two  or  more, 
111-15;  low-pressure  and  high- 
pressure,  111 


INDEX 


307 


Cylinder,  Explosion  within  the,  55— 

56,  151-53 

Cylinder  gates  for  turbines,  241 
Cylindrical  sleeve  valve,  172 

Dams  for  low-head  development, 
225-30;  construction  of,  247-48; 
wheels  may  be  within,  249 ;  loca- 
tion of  wheels  with  respect  to,  251- 
52 ;  power-house  inside,  260 
Davidson  and  Chase  on  "Farm  Ma- 
chinery," 303-4 

Day-work  and  piece-work,  297-300 
Design,  True,  59 
Double-acting  cylinder,  43—44 
Double-acting  gas-engine,  155—58 
Double-acting  tandem  twin  engines, 

156-58 
Draft,  Furnace,  67,  85 ;    heat  loss  in 

maintaining,  138-39 
Draft  tubes,  252-53,  262 ;    concrete, 

263-64 

Drums  in  curved-tube  boilers,  79-80 
Dry  vacuum-pump,  129,  130 
Dynamos  or  electric  generators,  270- 
71 

Economizer,  The,  103-5 

Economy,  a  controlling  idea,  68-69 ; 
how  measured,  137 

Efficiency,  in  boilers,  83  ;  principles 
of,  in  steam-power  systems,  101- 
41  ;  in  use  of  heat  from  coal,  102  ; 
of  jet  energy  of  steam,  117;  low 
limit  of,  in  steam  power,  142 ; 
higher  limit  of,  in  gas  system,  142— 
43,  174-75  ;  of  a  turbine,  244 

Electric  igniters,  172-73 

Electric  light,  Power-generated,  5 

Electric  motor,  Basal  principle  of  the, 
271 

Electric  plant,  Relation  of  engines 
and  boilers  in  a  large,  51,  52 

Electrical  Development  Co.  of  On- 
tario, Large  vertical  two-wheel 
turbine  for  the,  239-40 

Electrical  transmission  of  power,  219- 
20,  269-72 

Electricity,  a  manifestation  of  energy, 
7,  65 

Emerson,  Harrington,  or  reduction  of 
labor  waste,  294 


Employer  and  employed,  286-89  ; 
H.  L.  Gannt  on,  294-301 

Employment,  Creation  of,  26 

Energy,  Man's  control  of  the  sources 
of,  4-5  ;  natural,  not  dreamed  of, 
7  ;  interchangeable  manifestations 
of,  7,  65  ;  discovery  of  availability 
of,  in  nature,  7 ;  power  generation 
from,  8,  54-55  ;  nature's  stores  of, 
26 ;  work  from  each  unit  of,  32  ; 
of  motion  can  be  communicated, 
34-35 ;  three  old  principles  of 
conversion  of,  34-42,  54 

Energy  form,  Change  of,  for  trans- 
mission of  power,  269 

Engine  or  machine,  Essentials  of  a 
good,  31-32 

Engineering,  The  profession  of,  59 

Engineering  design,  The  basis  of,  59 

Engineers  of  more  importance  than 
generals,  4 ;  how  developed,  59 ; 
trained,  141 

Engines,  Standard  horizontal  and 
vertical,  47;  piston,  86-98.  See 
also  Gas-engine,  Steam-engine 

Ericsson,  John,  Hot-air  engine  of,  143 

Erie  R.  R.  locomotive,  18,  20 

Exhaust,  Reduction  of  pressure  in 
the,  increases  efficiency,  125 

Expansion  of  steam,  108-11  ;  multi- 
ple, 111-15 

Expansion  stroke  in  gas-engine,  151— 
53 

Explosion  of  gas  within  the  cylinder, 
55—56 ;  means  of  rapid  heating  in 
gas  system,  144-46 

Explosive  mixtures,  145-49 ;  mix- 
tures of  air  and  fuel  compressed 
in  cylinders  before  ignition,  146-47  ; 
puffed  into  cylinder  during  portion 
of  stroke,  159—60  ;  means  for  mak- 
ing the,  161—69;  chemical  constitu- 
ents, 161 ;  combustion  spherical, 
161-62;  of  weak,  hastened  by 
compression,  163  ;  time  of  ignition, 
164 ;  limits  of  compression,  165- 
66 ;  physical  properties  of,  valu- 
able, 166  ;  mechanism  for  propor- 
tioning mixtures  as  drawn  in,  166— 
69 ;  primary  principle  of  propor- 
tioning, 167 ;  inlet  and  sliding 
valves  for,  167-69 


308 


INDEX 


Explosive  or  detonating  wave,  The, 
162 

Factories,  Evolution  of,  2,  281-82; 
removing  from  cities  to  small 
towns,  301-2 

Factory,  Definition  of  a,  11  ;  devel- 
opment of  the,  281-82 

Factory  system  displaced  the  domes- 
tic, 282 

Factory  workers,  Classes  of,  286-89 

Fairs  or  markets  for  exchange,  60, 
280 

Fall  River,  Water-wheel  for  cotton 
manufacture  at,  230 

Farm  products,  Value  of,  10,  13 

Farm  workers,  the  largest  class,  281 ; 
drawn  to  factories  and  towns,  281- 
82 ;  decrease  in  number  of,  303 

Farmers  resorting  to  mechanical 
power,  9 

Farming  efficiency,  Increase  in, 
303-4 

Feed-water  heaters,  104-5 

Fire,  Capacity  of,  6,  7 

Fire-box,  The  locomotive,  74 

Fire-tube  boilers,  18,  73-75,  81 

Fisheries,  Use  of  power  boats  in,  8 

Float-valve  chamber  in  gas-producer, 
191 ;  in  carbureter,  201-3 

Flues,  Boiler,  71-75 

Fluids,  how  put  in  motion,  29—30 ; 
high  pressure  chambers  for,  30 ', 
moving,  have  energy  by  reason  of 
their  motion,  35 ;  getting,  under 
pressure,  37,  54 ;  generation  of 
power  by  moving,  41-42  ;  push  of, 
on  pistons  in  cylinders,  43  ;  push 
of,  under  pressure,  266-69 

Flume  of  the  San  Joaquin  Co.,  257-58 

Fly-shuttle  invented  by  Kay,  61 

Fore  River  Ship  Building  Co.,  51 ; 
steam  turbine  for  the  North  Dakota 
from  the,  122-24 

Forebay,  The,  249,  262,  263 

Forest  products,  10,  13 

Form  changing,  Simple  processes  of, 
6,  7 

Four-cycle  engine,  151-52 

Freight  haulage  in  1900,  20 

Frizell,  J.  F.,  Table  of  stream  flow  in 
Massachusetts,  217 


Fuel,  principal  source  of  natural 
energy,  23-24 ;  the  sun  the  source 
of  the  energy  in,  24 ;  sources  of 
supply  of,  26  ;  to  get  motion  from, 
31 ;  steam  from  combustion  of,  48  ; 
combustion  of,  84-85 ;  consists  of 
combustible  substances,  145  ;  con- 
servation of,  175  ;  gasifying  every 
grade  of,  possible,  199 

Fuel-burning  power  system,  The 
most  economical,  56 

Fuels,  Liquid,  mixed  for  use  by  ex- 
ternal apparatus,  201 ;  the  carbu- 
reter, 201-5 

Fuels,  solid  and  liquid,  Adaptation  of, 
for  the  use  of  internal  combustion 
engines,  177-210 

Fulton,  Robert,  bought  engine  for 
the  Clermont  from  Watt,  63 

Furnaces,  Loss  of  heat  in,  84—85 

Gannt,  H.  L.,  on  employer  and  em- 
ployed, 295-300 

Gary  Steel  Plant,  Double-acting 
tandem  twin  engines  at,  157-58 

Gas,  Per  cent  of  power  generated  by, 
as  a  fuel,  23  ;  pressure  of,  increased 
by  heating  when  confined  in  a 
chamber,  143,  148 ;  from  gas-pro- 
ducers, 184—85 ;  passes  through 
vaporizer,  188-89  ;  through  spray- 
tower  and  cleanser,  190 ;  tar  in, 
192 ;  static  cleaners  for,  193  ; 
filter  cleaners,  193-94  ;  mechanical 
cleaners,  194 ;  fluctuations  in 
quality  of,  195 ;  from  roasting 
bituminous  coal,  183,  192-95; 
making  a  constant  weak,  198—99 

Gas-engine,  of  Lenoir,  56,  57 ;  prime 
element  of  the  fuel-burning  power- 
system,  56  ;  involves  apparatus  to 
create  explosive  mixture,  146-47 ; 
elements  of  the,  149-50  ;  processes 
in,  150-60 ;  cylinder,  piston  and 
valves,  in  four-cycle  single-acting 
engines,  150-55 ;  will  run  best 
when  mixture  is  constant,  166 ; 
mixtures  proportioned  as  drawn 
into,  166 ;  inlet  and  sliding  valves 
for,  167—69 ;  mixture  supply  con- 
trol appliances  for,  170—72 ;  effi- 
ciency of,  174-75 ;  first  operated 


INDEX 


309 


with  illuminating  gas,  177-78; 
with  natural  and  blast-furnace 
gas,  178—83 ;  with  gas-producer 
gas,  184—99  ;  gas  from  oils  vapor- 
ized, 201-9;  great  efficiency  of ,  210 

Gas-engines  of  the  Lacka wanna  Steel 
Co.,  56,  58 

Gas-power  system,  30  ;  how  pressure 
is  produced  in  the,  54-56,  143  ; 
processes  and  mechanism  of  the, 
142—76  ;  two  basal  principles,  144  ; 
efficiency  per  unit  of  heat,  144 ; 
explosive  mixtures,  145-47 ;  161- 
69;  gas-engines,  149-60,  167-72; 
efficiency  of,  174-76;  two  sources 
of  gas  for,  178-79 ;  efficiency  of 
producers  and  engines,  199,  210 

Gas  power- transmission  system,  272 

Gas-producer,  Description  of,  184— 
86  ;  clinker  prevention,  186  ;  steam- 
jet  blower,  187 ;  without  grates, 
187-88 ;  suction,  188 ;  vaporizer, 
188-90,  191,  192;  cooling  and 
cleansing  tower  chamber,  190,  193  ; 
varieties  of,  192;  value  of,  200; 
209 

Gas-tar,  183 

Gases  in  vacuum  chamber,  129 

Gaskell,  P.,  on  "Artisan  and  Ma- 
chinery," 291 

Gasolene  distilled  from  oil,  200 

Gasolene  engines  for  farm  use,  9,  204  ; 
carbureters  for,  201-4 ;  industrial 
effects  produced  by,  204-5 

Gearing  for  transmission  of  power, 
267 

Generation,  see  Power-generating 
machinery 

Generators,  Electric,  or  dynamos, 
270-71 

Germany,  Use  of  blast-furnace  gas 
in,  179—80;  suction  gas-producers 
in,  188 ;  gas  power-transmission 
in,  272 

Governors  and  valves,  47,  170,  171, 
172  ;  for  regulating  flow  of  water, 
242,  246 

Great  Barrington,  Mass.,  First  high 
tension  long-distance  transmission 
at,  272 

Great  Jezero  Lake,  Head-gate  ar- 
rangement at  the,  254-55 


Great  Western  Power  Co.,   Turbine 

for,  the  largest  ever  built,  235 
Gunpowder,  147-48 
Gunpowder  engine  of  Huygens,  55 

Hackensack  Water  Co.,  Pumping- 
engine  of  the,  53 

Hand  and  finger  movements  repro- 
duced mechanically,  7-8 

Hand  labor,  60 

Hand  loom  and  spinning-wheel,  60 

Hanford  Irrigation  &  Power  Co., 
Turbine  built  for  the,  236-37 

Hargreaves  invented  spinning  ma- 
chine, 61 

Head,  see  Hydraulic  head 

Head-gate  arrangement  at  the  Great 
Jezero  Lake,  254-55 ;  at  Saulte 
Rapids,  255-56 

Head-gates,  249 

Head-race,  The,  249-51 

Head-works,  Variation  in  structure 
of,  257 

Heat,  a  manifestation  of  energy,  7, 
8 ;  nature  of,  and  relation  to  work 
discovered,  65,  142 ;  percentage 
of,  liberated  by  combustion  of 
coal,  in  steam,  83  ;  loss  of,  in  fur- 
naces, 84-85 ;  per  cent  of,  from 
coal,  utilized,  in  steam  engines, 
102 ;  reduction  of  loss  of,  and  use 
of  waste,  103-8 ;  saving  flue-gas, 
by  heating  boiler  water,  103—4; 
per  cent  of,  from  coal,  lost,  137—38  ; 
high  limit  on  waste  of,  in  steam 
power,  142 ;  necessary  to  vapori- 
zation of  the  heavy  oils,  205-6; 
methods  of  applying,  206-8 

Heat  energy,  Unconscious  use  of,  6-7 

Hero,  Steam  reaction  turbine  of,  41,  56 

High-pressure  boilers,  Use  of,  95 

High-pressure  chambers  for  fluids,  30; 
velocity  of  jet  from,  determined  by 
the  pressure,  36-37 

High-pressure  fluid,  Idea  of  securing 
motion  from,  30 

High-pressure  steam,  Expansion  of, 
95-97 

History,  The  Topics  of,  1-2 

Holyoke,  Mass.,  Canals  at  three 
levels  at,  230-31 ;  h.  p.  developed 
at,  231 


310 


INDEX 


Horizontal  engines,  50,  52 

Horse-power,  Statistics  of,  10-11 ; 
of  a  turbine,  244 

Hot-air  engine,  Ericsson's,  143 

Hot-well  pump,  126 

Huygens,  Gas-engine  of,  55 

Hydraulic  head  defined,  212  ;  classes 
of,  220  ;  medium,  at  Niagara  Falls, 
221-22  ;  extremely  high  available 
only  in  mountains,  224-25 ;  low- 
head,  225-30 

Hydraulic  pistons  for  moving  gates 
of  largest  turbine,  235-36 

Hydraulic  processes,  Basal,  211- 
265 

Hydraulic  system  of  transmission, 
267-68 

Hydrocarbons,  by-products  in  mak- 
ing coal-gas,  183 

Igniter,  The,  in  gas-engine,  153,  160 ; 
varieties  of,  172-73 

Ignition,  Proper  time  for,  164 ;  nat- 
ural temperature  of  mixture  for 
self,  165 ;  sets  a  limit  to  compres- 
sion, 166;  systems  of,  172 

Illuminating  gas  used  as  a  fuel,  177- 
78;  could  not  compete  with  coal, 
178 

Impulse  principle,  34,  38-42 ;  suc- 
cessive, 120 

Impulse  steam-turbine  of  Branca,  41- 
42 

Impulse  wheels,  38,  39,  120 ;  a  crude 
Indian,  231—32  ;  more  recent  forms, 
232  ;  series  of,  for  the  San  Joaquin 
plant,  245-46 

Industrial  age,  Our  times  the,  4 

Industrial  conditions,  Importance  of, 
in  shaping  affairs,  2 ;  value  of 
understanding  present,  3  ;  changes 
in,  276;  often  discussed,  277 

Industrial  revolution,  276-78 

Industrial  undertakings  dependent 
on  men  of  every  degree  of  ability, 
26-28 

Industries,  The  manufacturing  and 
transportation,  world-shaping 

forces,  4  ;  dependent  on  power,  9  ; 
capital  valuation  of,  9 ;  wage- 
earners  and  value  of  products  of, 
11-12 


Industries,  Mechanical  power  im- 
portant to  all,  8,  9 

Interborough  R.  R.,  Distribution  of 
energy  from  a  pound  of  coal  at 
central  power-station  of,  137—38 

Invention,  pure,  Little  progress 
without,  59 

Iron  goods,  Early  manufacture  of,  61 

Iron  industry,  Power  machinery  in, 
62 

Jet,  Water,  like  a  bar  of  steel,  246-47 
Jets,  Velocity  of,  determined  by  the 
pressure,  36 ;    energy  of,  37 ;    re- 
lation of,  to  that  of  vanes,  39,  99 ; 
turn  wheels  by  reaction,   42,   54; 
equals  that  of  rifle  bullet,  99-100 ; 
at  atmosphere  and  vacuum,  117 
Jump  spark,  The,  173 

Kaiser    Wilhelm,    The,    17-18;     fire- 
tube  boilers  of,  18,  81 
Kay  invented  the  fly-shuttle,  61 
Kerosene  distilled  from  oil,  200,  205 
Kilbourn,  Wis.,  Variation  of  stream 

flow  at,  216-17 

Knowledge  more  important  than 
mechanical  ability,  29 

Labor  unions,  296-98 

Labor  waste,  Reduction  of,  28  ;  enor- 
mity of,  294;  remedies  for,  295- 
300 

Laborers,  Classes  of,  280 ;  abuses  of, 
before  the  factory  era,  291 

Lackawanna  Steel  Co.,  Gas-engines 
of  the,  56,  58 

Lakes  Joux  and  Brenets,  Switzer- 
land, Pipe-lines  at,  259 

Lenoir,  Operative  gas-engine  of,  56, 
57 

Leopold,  Steam-pumping  engine  of, 
44 ;  worked  by  steam  pressure,  47 

Life  the  best  example  of  change  of 
substance  through  natural  energy, 
7 

Light,  a  manifestation  of  energy,  7, 
65 

Light-weight  self-contained  engine 
made  possible,  204 

Living,  What  comfortable,  involves, 
6 ;  conditions  of,  before  time  of 


INDEX 


311 


Watt,  60-61,  280-83  ;  daily  supply 

of,  for  the  world,  275-76 
Locomotive,  The  modern,  18-20,  47  ; 

construction  of,  48 ;  the  first,  63 
Locomotive  boilers,  74 
London,  Hydraulic  system  in,  268 
Losses  in   converting  one   pound   of 

coal  into  electricity,  137-39 
Low-head       water-power,       225-30 ; 

water-passages  for,  large,  244 
Lowell,     Kansas,     Development     at, 

259-61 
Lowell,   Mass.,  First  water-wheel  at 

site  of,  230 
Lowell  and  Suburban  Traction  Co., 

Boilers  for  power-house  of,  79 

McCall's  Ferry,  Low-head  develop- 
ment at,  226-28 ;  cities  supplied 
with  power  from,  227  ;  spillway  at, 
227,  247  ;  tail-race  at,  259  ;  power- 
house at,  263 

Machine  or  engine,  Essentials  of  a 
good,  31-32 

Machinery,  Relation  of,  to  social 
conditions,  1-28 ;  power-generat- 
ing, 4 ;  driven,  5 ;  problem  of 
power,  31—32  ;  wide  interest  in,  62 

Magnet,  Relation  of,  to  electric  cur- 
rents, 270-72 

Magnetism,  a  manifestation  of  energy, 
7,  65 

Make-and-break  spark,  172-73 

Manhattan  Elevated  R.  R.  plant, 
51,  52 

Manufactures,  Infinite  variety  of,  5-6 

Manufacturing,  Definition  of,  8 ; 
owes  existence  to  power,  9 ;  early, 
by  hand  labor,  60-61 

Manufacturing  establishments,  Num- 
ber of,  employees,  pay-rolls,  9 ; 
some  characteristic,  20—22 

Marine  boilers,  73—74 ;  grates  under 
entire,  81 ;  circulation  in,  81-83 

Marine  engine,  Requisites  for  the, 
48 

Markets  or  fairs  for  exchange  of 
products,  60 

Massachusetts,  Monthly  stream  flow 
in,  217 

Materials,  Changing  useless,  into  use- 
ful, 8 


Mead,  Prof.  Elwood,  on  variation  of 
stream  flow  at  Kil bourn,  Wis., 
216-17;  diagrams  of  stream  de- 
velopment, 249 

Mechanical  elements  must  have  sim- 
plicity, 30-31 

Mechanical  engineers,  Development 
of,  33-34 

Mechanical  invention,  The  story  of, 
3-4 

Mechanical  power,  Relation  of,  to 
social  conditions,  1—28 ;  substitu- 
tion of,  for  hand  labor,  3  ;  impor- 
tant in  all  industries,  8-9  ;  62 

Mechanism  subordinate  to  ideas,  29, 
30 

Men  of  different  qualifications  neces- 
sary to  organization,  27-28  ;  prob- 
lem of  best  use  of,  279 ;  classes  of 
laborers,  280-81  ;  effects  of  intro- 
duction of  machinery,  281-82 ; 
transportation,  282-83  ;  commerce, 
283-85  ;  capital  and  labor,  286-89  ; 
trade-unionism,  289-94  ;  employer 
and  employed,  294-301 

Merrimac  River,  Areas  of  watersheds 
drained  by  the,  218 ;  water-power 
on  the,  at  Lowell,  230 

Midvale  Steel  Co.,  Reduction  of  labor 
waste  by  the,  295 

Milwaukee  Railway,  Double-acting 
tandem  twin  engine  in  power  plant 
of,  157 

Mine  products,  Cost  of,  10,  13 

Mines,  Use  of  power  in,  8 

Montmorency  Falls,  Water-power  at, 
223 

Morris,  I.  P.,  Co.,  builders  of  largest 
water  turbine,  235 

Motion,  The  energy  of,  commun- 
icable, 34-35  ;  processes  to  produce, 
against  resistance,  31,  54-55;  by 
atmospheric  pressure,  45-46 ;  re- 
ciprocating, changed  to  rotary, 
47 

Motive  power  in  U.  S.,  Diagram  of 
total  prime,  25 

Motor  boat,  Gasolene  engine  funda- 
mental to  the,  204 

Moving  fluids  have  energy  by  reason 
of  their  motion,  35 

Multiple  expansion,  111-15,  136 


312 


INDEX 


Natural  gas,  Localities  of,  178 ;  cost 
of,  178 

Natural  sciences,  Development  and 
study  of  the,  33-34,  64-65 

Nature,  Man's  control  over  forces  of, 
4-5 

Nature's  stores,  Man's  use  of,  6 ;  of 
substances  and  energy,  26 

Needle-valve  for  carbureter,  202,  203 

Neuhausen  on  the  Rhine,  Low-head 
development  at,  226 

New  York  Central  locomotive,  A, 
18-20 

New  York  Edison  Power  Station, 
Mechanical  stoker  for,  105-6 

New  York  Subway  power-house,  16, 
17  ;  turbine  auxiliary  to  compound 
engine  in,  124-25 

Newcomen's  single-acting  cylinder 
engine,  44-45 ;  worked  by  atmos- 
pheric pressure,  46-47,  55 

Niagara  Falls,  a  larga-flow,  abrupt- 
drop,  medium-head  water-site,  221— 
22;  two-wheeled  turbine  at,  239- 
40  ;  a  natural  spillway,  247 

Niagara  Falls  Power  Co.,  Large  tur- 
bine for,  238  ;  cross-section  of,  241- 
42 

Non-producing  consumers,  280 

North  Dakota,  The,  and  steam-turbine 
for,  122-24 

Nozzle  with  needle-valve  in  carbu- 
reter, 202 

Nozzles,  Outlets  for  jets  of  fluids,  36, 
38;  action  of  jets  on,  39-42,  54; 
complete  expansion  of  steam  in, 
99;  forms  of,  for  steam,  118-21; 
small  areas  of,  for  very  high-head 
water  work,  245 ;  single,  for  high- 
head  wheels,  245-46 ;  deflection 
of,  245-46 

Oil,  Natural,  as  fuel,  200;  sub- 
stances distilled  from,  200  ;  vapor- 
izing heavy,  205-6 ;  very  heavy, 
injected  into  heated  combustion 
chamber,  206-8 ;  cartridge 

method,  209 

Oil-engine  using  compressed  hot  air, 
207 

Ontario  Power  Co.,  Water-power  of 
the,  256 


Organization    to    reduce    waste    of 

human  effort,  28 
Overshot   wheels   in   early   low-head 

development,  229  ;    compared  with 

turbine,  233-34 

Pacolet  Mills,  Horizontal  water-tube 
boilers  for  the,  77,  78 

Paddle  wheels,  Motion  given  to,  by 
moving  water,  34 

Paraffine  obtained  from  natural  oil, 
200 

Paris,  Compressed  air  system  in, 
269 

Parker,  E.  W.,  Estimate  by,  of  dura- 
tion of  coal  supply,  25 

Paterson,  Water-wheel  for  cotton 
manufacture  at,  230 

Pawtucket  Falls,  First  water-whsel 
for  cotton  manufacture  erected  at, 
230 

Physical  processes  discovered,  29-30 

Piece-work  and  day-work,  297—300 

Pioneer  Electrical  Power  Co.  of  Utah, 
Pipe-line  of  the,  of  staves,  261 

Pipe-line  of  San  Joaquin  Electric  Co., 
225  ;  weight  of  water  in,  243 

Pipe-lines,  Regulating  flow  of  water 
in,  243  ;  at  Lakes  Joux  and  Brenets, 
259  ;  of  staves,  261 

Piping  systems,  67,  85 

Piston,  The  reciprocating,  47 ;  and 
two  valves,  in  four-cycle  single- 
acting  gas-engines,  150-55 ;  in 
double-acting,  155-56 

Piston  engines,  86-98 

Piston  engines,  Combined  vertical 
and  horizontal,  51,  52 

Piston  speed  of  an  engine,  Variations 
in,  164 

Piston-valve,  The,  86 

Pistons  in  cylinders,  43-46,  47,  54 

Port  Morris  power  station  of  N.  Y. 
Central  R.  R.,  130-31 

Potomac  Electric  Co.,  Steam  turbine 
of  the,  36-37 

Powder-guns,  43 

Power-driven  machinery,  Products 
of,  5-6,  26;  invention  of,  61 ;  suc- 
cess of,  62 ;  in  iron  industry,  62  ; 
changes  effected  by,  276-82 

Power  employed,  Statistics  of,  10-11 ; 


INDEX 


313 


per  cent  of,  derived  from  combus- 
tion of  fuel,  22-23 ;  increase  in, 
24-25 

Power-generating  machinery  gives 
control  over  forces  of  nature,  4-5  ; 
variety  of  results  from,  5-6 ;  from 
source  of  energy  with  least  net 
waste,  26 ;  substitution  of,  for 
labor  of  men,  29—65 ;  mechanism 
subordinate  to  idea  of  physical 
process,  29  ;  elements  in  problem 
of  development  of,  31-32  ;  develop- 
ment of  mechanical  engineers,  33- 
34  ;  the  earliest,  result  of  pure  in- 
vention, 57-59  ;  Watt  engines  in 
textile  factories,  61 ;  success  of, 
62  ;  old  and  new,  64  ;  steam-power 
machinery,  65-100 ;  social  and 
economic  consequences  of  substi- 
tution of,  for  hand  labor,  266-304  ; 
object  of,  266  ;  complexity  of  the 
situation  in,  274  ;  one  best  way  for 
each  case,  275 ;  little  popular 
knowledge  of,  277-78 

Power  generation,  denned,  8 ;  one 
of  earliest  ideas  applied  to,  34 ; 
simplest,  oldest,  and  most  modern 
ideas  of,  41-42 

Power  loom  perfected  by  Cartwright, 
61 

Power-machinery,  see  Power-generat- 
ing machinery 

Power  plant,  the  vital  organ  of  a 
complex  organism,  14 

Power  transmission  systems,  266-69  ; 
variety  of,  272 

Preignition,  165 

Pressure,  exerted  by  water  or  other 
fluid,  36  ;  velocity  determined  by, 
36 ;  how  secured  in  the  several 
systems,  54-55 ;  from  exploding 
confined  gases,  148 

Principles  discovered  and  classified, 
64-65 ;  thermodynamics,  65 

Processes  fundamental,  mechanisms 
incidental,  30 

Producers  and  non-producers,  280 

Products  of  manufacturing  industries, 
Value  of,  11,  12 

Products  of  power-driven  machinery, 
5-6 

Progress,  True,  when  possible,  59 


Prosperity,    National,   a  prerequisite 

to  civilization,  8 
Providence,   First  steam-engine  mill 

erected  at,  231 
Public  Service  Corporation,  Newark, 

N.  J.,  Economizers  for  the,  103-4 
Puget  Sound  Power  Co.,   Intake  of 

the,  253-54 
Pumping-engines,  47  ;    of  Allis-Chal- 

mers  Co.,  53 
Pumps  auxiliary  to  condensers,  126- 

30 
Putnam,  H.  St.  Clare,  Table  of  power 

in  use,  11 
Pyro,   denatured  alcohol,  201 

Questions  of  vital  importance,  1—2 

Racks  or  screens  for  intercepting  ice 

and  rubbish,  249,  254,  256 
Railroads,    Mileage,    employees    and 

wages,    9 ;     passenger    mileage    in 

1900,  20 
Rainfall,   Concentration  of,   211-12; 

irregular,  214-15;    of  U.  S.,  218 
Raw  materials,  Cost  of,  for  1905,  10 ; 

source  of,   13  ;    increased  in  value 

by  manufacture,  13-14 
Reaction,  principle  of,  Use  of,  39-41, 

54 

Reaction  steam-turbine  of  Hero,  41 
Reaction    wheels,    39-42,    232,    261; 

modern  combined  impulse  and,  233 
Register  gates  for  turbines,  241 
Relief-valves  for  flow  of  water,  244 
Republic  Iron  and  Steel  Co.,  Blowing- 
engine  of  the,  53,  54 
Reservoirs,  Storage,  214,  216,  217,  247 
River  steam-boat,  The  modern,  63,  64 
"Rocket,  The,"  first  locomotive,  by 

Stephenson,  63 
Rocky   Mountains,   High  head-work 

in  the,  225 

Ropes,  Transmission  of  power  by,  267 
Rotating  shafts,  Early  uses  of,  60 
Ruskin,     John,     blamed     industrial 

progress,  291 

St.  Clair  Steel  Co.,  Curved-tube 
boilers  for  the,  80 

Samson  Co.,  Wheel  runners  of  tur- 
bines built  by,  237-38 


314 


INDEX 


San  Joaquin  Electric  Co.,  Pipe-line 
of,  225 ;  impulse  wheels  for,  245— 
46;  flume  for  the,  258 

Saulte  Rapids,  Water-gate  and  power- 
house at,  254—56 

Scale  in  boilers,  77 

Science  based  on  related  facts  and 
general  principles,  59 

Scotch  marine  boiler,  73-74,  75 

Screen  or  rack  for  logs  and  ice,  249, 
254,  256 

Sea  products,  10,  13 

Seeds,  Growth  of,  through  heat  energy, 
6-7 

Self-ignition,  165 

Shawinegan  Falls,  Canada,  Large 
water-wheel  at,  35-36 

Single-acting  cylinder,  43,  45 

Slide-valve,  The,  86-91  ;  variation  of 
form  of,  89-90 ;  use  of  two,  97-98 

Smeaton's  cylinder  blower,  62 

Smith,  E.  S.,  on  growth  of  cities, 
302-3 

Social  conditions,  Growth  of  cities  de- 
pendent on,  302-3 

Soot  formed  in  gas-producer  with 
down  draft,  197 

Sound  a  manifestation  of  energy,  7 

Spillway  for  waste  water,  226,  247, 
248 

Spinning  machines  invented,  61 

Spinning  room  at  New  Bedford,  22, 
23 

Spray-nozzle  system  of  condensing, 
132-33 

Spray  tower  chamber  in  gas-pro- 
ducer, 190,  193 

Sprayed  air  -mixtures,  Methods  of 
heating,  205-6 

Stack,  Loss  of  heat  to  the,  137,  138-39 

Stand-pipes,  244 

Stationary  engines,  Steadiness  and 
durability  in,  51 

Statistics,    Manufacturing,   9-11 

Statistics,  Railroad,  9-11 

Steam,  a  fluid  that  behaves  much 
like  water,  34  ;  how  set  in  motion, 
36 ;  use  of,  at  pressure  greater 
than  the  atmosphere,  44 ;  at  at- 
mospheric pressure,  45 ;  vacuum 
from  condensing,  45-46;  percent- 
age of  heat  liberated  by  combus- 


tion of  coal  in,  83,  102;  efficient 
use  of  pressure  of,  94-96 ;  expan- 
sion of,  96 ;  range  of  volume  of, 
95-96 ;  expansion  of,  to  atmos- 
phere, 108;  to  vacuum,  109,  110- 
11 ;  per  cent  of  work  done  by,  109- 
10 ;  expansion  of,  in  two  or  more 
cylinders,  111-15;  complete  ex- 
pansion of,  in  nozzles,  116;  veloc- 
ity of  expanding,  117  ;  loss  of,  134- 
36;  superheated,  136 

Steam-engine  mill,  The  first,  erected 
at  Providence,  231 

Steam-engines,  Variety  of,  47 ;  67, 
98  ;  the  larger,  consume  less  steam 
per  h.  p.,  68  ;  questions  of  economy 
and  efficiency  of,  85-86 ;  use  of 
steam  per  hour  per  h.  p.,  by  simple 
type,  102  ;  advances  in,  108 ;  mul- 
tiple expansion,  111-15 

Steam-jet  for  gas-producer,  185-87 

Steam-power  system,  30 ;  how  pres- 
sure is  produced  in  the,  54 ;  essen- 
tial elements  of,  66-100 ;  steam- 
generating  plant,  66-85 ;  prin- 
ciples of  efficiency  in,  101-41 ;  use 
of,  less  than  of  water-power,  101  ; 
sources  of  advances  in,  101-2 ; 
improvements  in,  of  two  classes, 
102-3  ;  study  for  net  economy  in, 
141 

Steam-pumping-engine,  44 

Steam  turbine,  34,  36;  of  Hero,  41, 
56,  98 ;  relations  of  wheel  and 
vanes  to  steam  jet,  99-100  ;  forms 
of,  115-25;  for  the  North  Dakota, 
122-24  ;  condensing  equipment  for 
exhaust  of,  128-29 

Steamship,  A  modern,  17-18 

Stephenson,  George,  built  first  loco- 
motive, "The  Rocket,"  63 

Stokers,  Mechanical,  105-7;  for 
N.  Y.  Edison  Power  Station,  105-6 

Stott,  H.  G.,  Table  of  heat  losses  from 
one  pound  of  coal,  137-38 

Stream  development,  249-51 ;  loca- 
tion of  wheels  with  respect  to  the 
dam,  251-52 

Stream  flow,  Minimum,  only  avail- 
able, 215-16 ;  per  cent  of  yearly, 
in  each  month,  in  Massachusetts, 
217  ;  fluctuations  of,  216-18 


INDEX 


315 


Streams,  Percentage  of  power  from, 
decreasing,  23 ;  estimated  water- 
power  capacity  of  our,  25-26 

Substance  form,  Change  of,  through 
natural  energy,  6-7 

Substances,  Nature's,  Knowledge  and 
use  of,  26 

Suction,  denned,  45-46 

Suction  gas-producer,  188 

Suction  stroke  in  gas-engine,  154 

Sun,  The,  source  of  all  energy,  24 

Sunshine,  Energy  of  the,  6-7 

Superheated  steam,  136 

Swift  &  Co.,  Chicago,  Meat-product 
plant  of,  21 

Systems,  Choice  of,  273-74 

Tail  pipe  to  condensers,  132-35 

Tail-race,  The,  249,  250,  251 

Tandem  compound  engine,   112 

Tar,  183 ;  in  bituminous  coal-gas, 
192  ;  static  and  filter  cleaners,  193- 
94;  mechanical  cleaners,  194-95; 
consumption  of,  by  downward 
draft,  195-96 ;  by  combination  of 
up-and-down  draft,  197 ;  by  com- 
bination of  beehive  oven  and  blast 
furnace,  198-99 

Taylor,  Fred  W.,  on  reducing  labor 
waste,  294-95 

Thermodynamics,  Development  of, 
65,  95  ;  application  of  laws  of,  98, 
141 :  one  of  greatest  contributions 
of,  143 

Throttle  valve,  170 

Tivoli,  Italy,  Falls  at,  224 ;  masonry 
viaduct  at,  258 

Towns,  Evolution  of,  281-82 

Trade-unionism,  289-94 

Transformers  of  electric  currents, 
271-72 

Transmission,  see  Power  transmis- 
sion 

Transportation,  Result  of  developed 
systems  of,  2,  5-6,  282-84 ;  power 
the  prime  element  in,  9 

Turbine,  First  hydraulic,  at  Apple- 
ton  Mills,  Lowell,  231 ;  principles 
of  the,  231-34;  impulse  and  re- 
action, 232-33  ;  examples  of,  234- 
40 ;  flexibility  of  construction  of, 
234,  240 ;  largest  ever  built,  235 ; 


gates  for,  240-44 ;  h.  p.  of  a,  244 ; 
efficiency,  244 

Turbine  wheel,  An  Indian  impulse, 
231-32;  and  overshot  compared, 
233-34  ;  submerged,  251-53  ;  hori- 
zontal shaft,  252-53 

Turbines,  36 ;  efficiency  of,  calcu- 
lable, 39,  42;  steam,  99-100,  115- 
25 ;  as  auxiliaries  to  compound- 
engines,  124 

Two-cycle  engine,  158-60 

Up-draft  pressure  producers,  184-88 
Upper-level  canal  or  head-race,  249 

Vacuum  chamber,  126 

Vacuum  from  condensed  steam,  45- 
46 

Vacuum-pump,  126 

Valves,  see  Corliss  valve,  Piston- 
valve,  Slide-valve 

Valves  in  gas-engines,  150-57 

Vanes  on  wheels,  38,  115-23;  rela- 
tion of  speed  of,  to  that  of  jet,  39, 
54,  99,  117-18;  forms  of,  117-19, 
121 ;  curvatures  of,  on  wheel 
runners,  237 

Vaporizer,   A  separate,   206 

Vaporizer,  Hot  bulb,  207-8 

Vaporizer,  or  carbureting  vaporizer, 
206 

Vaporizers,  Heavy  oil,  205-8;    210 

Vaporizers  in  gas-producers,  189-90, 
191,  192 

Vaporizing  automatic  in  carbureter, 
203  ;  of  heavy  oils  or  fuels,  205-9 

Variable  lift  inlet  valve,  171 

Vaseline  made  from  natural  oil,  200 

Velocity  of  jet  determined  by  the 
pressure,  36;  99-100,  117 

Vermont,  U.  S.  battleship,  49 ;  en- 
gines of  the,  48-50 

Vertical  engine  of  the  Walter  Baker 
Co.,  50,  51 

Vertical  water-tube  boilers,  78-79 

Wage  earners  in  manufacturing  in- 
dustries, 11-12;  increase  of,  281- 
82;  capital  and,  286-89;  trade- 
unionism,  289-94 ;  and  employers, 
294-301 


316 


INDEX 


Wars  the  only  extraordinary  happen- 
ings of  early  times,  2 

Waste,  Location  and  reduction  of, 
a  philosophic  law,  5 ;  utilization 
of,  14 ;  study  of  reduction  of,  and 
our  industrial  future,  26,  28;  va- 
rious distribution  of,  137—38 ;  the 
problem  of  minimum,  139 

Water  energy,  First  application  of, 
7,  16,  29 ;  per  cent  of  power  gen- 
erated from,  23  ;  motion  from,  31- 
42  ;  basal  idea  of  water-  and  steam- 
turbines,  34 

Water  headers,  76,  81-82 

Water-jacket  around  cylinder,  151, 
153 

Water-jet  like  a  bar  of  steel,  246-47 

Water-mill,  The,  15,  16 

Water-power  capacity  of  our  streams, 
25-26 

Water-power  system,  30,  54 

Water-power  systems  and  basal  hy- 
draulic processes,  211-65;  meas- 
ure of  stream  power,  212;  cost  of 
concentration  on  wheel,  213-14 ; 
storage  reservoirs,  214,  216,  217; 
•only  minimum  stream  flow  avail- 
able, 215-16;  monthly  stream 
flow  in  Massachusetts,  217 ;  sites 
for,  far  from  towns,  219  ;  relation 
of  electric  power  transmission  to, 
-219-20 ;  variable  cost  of,  264-65 

Water,  Pressure  exerted  by,  36; 
height  raised  to  by  atmospheric 
pressure,  46 ;  conducted  from  a 
high  to  a  lower  level,  54  ;  in  pipes, 
212 

Watersheds,  211    - 

Water-tube  boilers,  76-80 

Water-wheel,  The  first,  in  this  coun- 
try, erected  at  Pawtucket  Falls,  230 


Water-wheels,  34-36;  one  of  the 
largest,  at  Shawinegan  Falls, 
Canada,  35-36 

Watt,  James,  The  steam-engine  of, 
47  ;  first  rotative  steam-engine  of, 
57 ;  use  of  engines  of,  61 ;  sold 
engine  to  Fulton,  63  ;  demand  for 
engines  of,  98 

Weak  explosive  mixtures,  165 

Wealth,  Sources  of,  8 ;  definition  of, 
291 ;  production  of,  292-93  ;  share 
of  manufacturer  and  worker  in, 
292-93,  295-300 

Wealth  of  country,  how  increased, 
26 

Webb,  Sidney  and  Beatrice,  on  Trade- 
unionism,  289-90 

Webber,  Samuel,  Areas  of  Merrimac 
River  watersheds,  218 

Wheel,  Adaptation  of,  to  the  locality, 
247  ;  may  be  within  the  dam,  249  ; 
supply  of  water  to,  249-51 ;  loca- 
tion of,  with  respect  to  dam,  251-52 

Wheel  runners  of  turbines,  Peculiar, 
237-38 

Wheels  and  vanes  in  turbines,  115-23  ; 
velocity  of,  117-18 

Wheels,  High-head,  for  single  noz- 
zles, 245-46 

Wheels,  Impulse,  38,  39,  245-46 

Wheels,  see  also  Water-wheels 

Wicket  gates  for  turbines,  241,  242 

Wind  energy,  First  application  of,  7 ; 
to  get  motion  from,  31 

Windmill,  The,  15,  16 

Woolens,  Early  manufacture  of,  in 
England,  61 

Work,  a  manifestation  of  energy,  7, 
65 

Zambesi  Falls  in  Africa,  222-23 

C.  A.  N. 


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